diff --git a/.github/actions/save-macos-caches/action.yml b/.github/actions/save-macos-caches/action.yml
new file mode 100644
index 000000000..ea38f45be
--- /dev/null
+++ b/.github/actions/save-macos-caches/action.yml
@@ -0,0 +1,44 @@
+name: Save macOS build caches
+description: Save the caches that setup-macos restored without an exact match. Run it at the end of the job, after the build input times are saved.
+
+# The repository has a 10 GB cache quota, and the large entries (SwiftPM, CLI and App build
+# state) change with every source change. Only main saves them, so that pull requests do not
+# evict the entries of main, which all pull requests restore. The small Mise and GhosttyKit
+# entries change rarely, and a GhosttyKit miss is slow to rebuild, so pull requests save them.
+runs:
+  using: composite
+  steps:
+    - if: env.PROWL_MISE_CACHE_HIT != 'true'
+      uses: actions/cache/save@v4
+      with:
+        path: |
+          ~/.local/share/mise
+          ~/.cache/mise
+        key: ${{ env.PROWL_MISE_CACHE_KEY }}
+    - if: env.PROWL_GHOSTTY_CACHE_HIT != 'true'
+      uses: actions/cache/save@v4
+      with:
+        path: |
+          App/Frameworks/GhosttyKit.xcframework
+          App/Resources/ghostty
+          App/Resources/terminfo
+          .ghostty_hash
+          .ghostty_build_stamp
+        key: ${{ env.PROWL_GHOSTTY_CACHE_KEY }}
+    - if: env.PROWL_SPM_CACHE_HIT != 'true' && github.ref == 'refs/heads/main'
+      uses: actions/cache/save@v4
+      with:
+        path: ~/Library/Caches/prowl-spm-cache/SourcePackages
+        key: ${{ env.PROWL_SPM_CACHE_KEY }}
+    - if: env.PROWL_CLI_CACHE_HIT != 'true' && github.ref == 'refs/heads/main'
+      uses: actions/cache/save@v4
+      with:
+        path: |
+          CLI/.build
+          Mirror/Relay/.build
+        key: ${{ env.PROWL_CLI_CACHE_KEY }}
+    - if: env.PROWL_APP_CACHE_HIT != 'true' && github.ref == 'refs/heads/main'
+      uses: actions/cache/save@v4
+      with:
+        path: ${{ env.PROWL_DERIVED_DATA_PATH }}
+        key: ${{ env.PROWL_APP_CACHE_KEY }}
diff --git a/.github/actions/setup-macos/action.yml b/.github/actions/setup-macos/action.yml
index a095f5777..0474118a5 100644
--- a/.github/actions/setup-macos/action.yml
+++ b/.github/actions/setup-macos/action.yml
@@ -1,11 +1,12 @@
 name: Setup macOS build deps
-description: Install + cache mise tools and GhosttyKit build outputs
+description: Install mise tools and restore the build caches. Run save-macos-caches at the end of the job to save them.
 
 runs:
   using: composite
   steps:
     - name: Mise cache
-      uses: actions/cache@v4
+      id: mise_cache
+      uses: actions/cache/restore@v4
       with:
         path: |
           ~/.local/share/mise
@@ -31,7 +32,8 @@ runs:
         echo "Xcode cache identity: $XCODE_CACHE_ID"
 
     - name: CLI SwiftPM build cache
-      uses: actions/cache@v4
+      id: cli_cache
+      uses: actions/cache/restore@v4
       with:
         path: |
           CLI/.build
@@ -53,7 +55,7 @@ runs:
         printf '%s\n' "GHOSTTY_SHA=$GHOSTTY_SHA" >> "$GITHUB_ENV"
     - name: Ghostty cache
       id: ghostty_cache
-      uses: actions/cache@v4
+      uses: actions/cache/restore@v4
       with:
         path: |
           App/Frameworks/GhosttyKit.xcframework
@@ -76,26 +78,14 @@ runs:
         touch .ghostty_build_stamp
 
     - name: SPM cache
-      uses: actions/cache@v4
+      id: spm_cache
+      uses: actions/cache/restore@v4
       with:
         path: ~/Library/Caches/prowl-spm-cache/SourcePackages
         key: ${{ runner.os }}-${{ runner.arch }}-spm-v1-${{ hashFiles('.package.resolved') }}
         restore-keys: |
           ${{ runner.os }}-${{ runner.arch }}-spm-v1-
 
-    - name: Xcode compilation cache
-      uses: actions/cache@v4
-      with:
-        path: ~/Library/Developer/Xcode/DerivedData/CompilationCache.noindex
-        # GitHub cache entries are immutable. A source-state suffix guarantees that a
-        # successful changed build saves newly compiled objects; restore-keys select the
-        # newest compatible CAS. Never restore across Xcode builds because compiler cache
-        # keys and storage formats are toolchain-specific.
-        key: ${{ runner.os }}-${{ runner.arch }}-xcode-compilation-cache-v3-${{ env.XCODE_CACHE_ID }}-${{ hashFiles('.package.resolved', 'Tuist.swift', 'Workspace.swift', 'App/Project.swift', 'App/Config/**', 'mise.toml', 'Makefile', '.github/actions/setup-macos/action.yml', '.github/workflows/test.yml') }}-${{ hashFiles('App/**/*.swift', 'Shared/Sources/**/*.swift', 'Mirror/Shared/*.swift', 'Mirror/Relay/Sources/**/*.swift') }}
-        restore-keys: |
-          ${{ runner.os }}-${{ runner.arch }}-xcode-compilation-cache-v3-${{ env.XCODE_CACHE_ID }}-${{ hashFiles('.package.resolved', 'Tuist.swift', 'Workspace.swift', 'App/Project.swift', 'App/Config/**', 'mise.toml', 'Makefile', '.github/actions/setup-macos/action.yml', '.github/workflows/test.yml') }}-
-          ${{ runner.os }}-${{ runner.arch }}-xcode-compilation-cache-v3-${{ env.XCODE_CACHE_ID }}-
-
     - name: App incremental cache identity
       shell: bash
       run: |
@@ -105,7 +95,8 @@ runs:
         APP_WORKSPACE_ID="$(pwd -P | shasum -a 256 | cut -d ' ' -f 1)"
         printf '%s\n' "APP_INPUT_PATHS_ID=$APP_INPUT_PATHS_ID" "APP_WORKSPACE_ID=$APP_WORKSPACE_ID" >> "$GITHUB_ENV"
     - name: App incremental build cache
-      uses: actions/cache@v4
+      id: app_cache
+      uses: actions/cache/restore@v4
       with:
         path: ${{ env.PROWL_DERIVED_DATA_PATH }}
         # Incremental state needs a stricter boundary than the content-addressed cache.
@@ -113,6 +104,43 @@ runs:
         key: ${{ runner.os }}-${{ runner.arch }}-app-incremental-v2-${{ env.XCODE_CACHE_ID }}-${{ env.APP_WORKSPACE_ID }}-${{ env.GHOSTTY_SHA }}-${{ env.APP_INPUT_PATHS_ID }}-${{ hashFiles('CLI/Package.swift', 'CLI/Package.resolved', 'Shared/Package.swift', 'Mirror/Relay/Package.swift', '.package.resolved', 'Tuist.swift', 'Workspace.swift', 'App/Project.swift', 'App/Config/**', 'mise.toml', 'Makefile', '.github/actions/setup-macos/action.yml', '.github/workflows/test.yml', 'scripts/ci-source-mtimes.py') }}-${{ hashFiles('App/**/*.swift', 'Shared/Sources/**/*.swift', 'Mirror/Shared/*.swift', 'Mirror/Relay/Sources/**/*.swift') }}
         restore-keys: |
           ${{ runner.os }}-${{ runner.arch }}-app-incremental-v2-${{ env.XCODE_CACHE_ID }}-${{ env.APP_WORKSPACE_ID }}-${{ env.GHOSTTY_SHA }}-${{ env.APP_INPUT_PATHS_ID }}-${{ hashFiles('CLI/Package.swift', 'CLI/Package.resolved', 'Shared/Package.swift', 'Mirror/Relay/Package.swift', '.package.resolved', 'Tuist.swift', 'Workspace.swift', 'App/Project.swift', 'App/Config/**', 'mise.toml', 'Makefile', '.github/actions/setup-macos/action.yml', '.github/workflows/test.yml', 'scripts/ci-source-mtimes.py') }}-
+    # Xcode keeps the compilation cache (CAS) in the DerivedData folder, so the App incremental
+    # cache carries it. When no compatible incremental state exists (changed file roster or build
+    # configuration), keep only the CAS of the newest App build for this Xcode. The build is then
+    # clean, but it replays compiler outputs from the content-addressed cache.
+    - name: Compilation cache of an earlier App build
+      id: app_cas
+      if: steps.app_cache.outputs.cache-matched-key == ''
+      uses: actions/cache/restore@v4
+      with:
+        path: ${{ env.PROWL_DERIVED_DATA_PATH }}
+        key: ${{ runner.os }}-${{ runner.arch }}-app-incremental-v2-${{ env.XCODE_CACHE_ID }}-${{ env.APP_WORKSPACE_ID }}-
+        restore-keys: |
+          ${{ runner.os }}-${{ runner.arch }}-app-incremental-v2-${{ env.XCODE_CACHE_ID }}-${{ env.APP_WORKSPACE_ID }}-
+    - name: Keep only the compilation cache
+      if: steps.app_cas.outputs.cache-matched-key != ''
+      shell: bash
+      run: |
+        set -euo pipefail
+        find "$PROWL_DERIVED_DATA_PATH" -mindepth 1 -maxdepth 1 ! -name CompilationCache.noindex -exec rm -rf {} +
+        du -sh "$PROWL_DERIVED_DATA_PATH/CompilationCache.noindex" 2>/dev/null || echo "No compilation cache in the restored state"
     - name: Restore unchanged App source times
       shell: bash
       run: python3 scripts/ci-source-mtimes.py restore --scope app --manifest "$PROWL_DERIVED_DATA_PATH/source-times.json"
+
+    - name: Cache keys for save-macos-caches
+      shell: bash
+      run: |
+        set -euo pipefail
+        {
+          echo "PROWL_MISE_CACHE_KEY=${{ steps.mise_cache.outputs.cache-primary-key }}"
+          echo "PROWL_MISE_CACHE_HIT=${{ steps.mise_cache.outputs.cache-hit }}"
+          echo "PROWL_CLI_CACHE_KEY=${{ steps.cli_cache.outputs.cache-primary-key }}"
+          echo "PROWL_CLI_CACHE_HIT=${{ steps.cli_cache.outputs.cache-hit }}"
+          echo "PROWL_GHOSTTY_CACHE_KEY=${{ steps.ghostty_cache.outputs.cache-primary-key }}"
+          echo "PROWL_GHOSTTY_CACHE_HIT=${{ steps.ghostty_cache.outputs.cache-hit }}"
+          echo "PROWL_SPM_CACHE_KEY=${{ steps.spm_cache.outputs.cache-primary-key }}"
+          echo "PROWL_SPM_CACHE_HIT=${{ steps.spm_cache.outputs.cache-hit }}"
+          echo "PROWL_APP_CACHE_KEY=${{ steps.app_cache.outputs.cache-primary-key }}"
+          echo "PROWL_APP_CACHE_HIT=${{ steps.app_cache.outputs.cache-hit }}"
+        } >> "$GITHUB_ENV"
diff --git a/.github/workflows/mirror-android.yml b/.github/workflows/mirror-android.yml
new file mode 100644
index 000000000..2d88f9090
--- /dev/null
+++ b/.github/workflows/mirror-android.yml
@@ -0,0 +1,44 @@
+name: mirror-android
+
+# The Android mirror client needs only a minimal check, so CI runs it only when the client
+# changes and for each published release.
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - Mirror/Android/**
+      - .github/workflows/mirror-android.yml
+  pull_request:
+    paths:
+      - Mirror/Android/**
+      - .github/workflows/mirror-android.yml
+  # Release tags are lightweight, so `git push --follow-tags` does not push them and
+  # `gh release create` makes them on GitHub. That sends no tag push event.
+  release:
+    types:
+      - published
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  mirror-android:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-java@v6
+        with:
+          distribution: temurin
+          java-version: '17'
+          cache: gradle
+      - uses: android-actions/setup-android@v4
+      - name: Install Android SDK 34
+        run: sdkmanager 'platforms;android-34' 'build-tools;34.0.0'
+      - name: Build and test Android mirror
+        working-directory: Mirror/Android
+        run: ./gradlew --no-daemon :app:assembleDebug :app:testDebugUnitTest :app:lintDebug
diff --git a/.github/workflows/mirror-ios.yml b/.github/workflows/mirror-ios.yml
new file mode 100644
index 000000000..08e6d2e0f
--- /dev/null
+++ b/.github/workflows/mirror-ios.yml
@@ -0,0 +1,64 @@
+name: mirror-ios
+
+# The iOS mirror client needs only a minimal check, so CI runs its unit tests only when the
+# client changes and for each published release. The UI suite runs locally with
+# `make test-mirror-ios`.
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - Mirror/iOS/**
+      - Mirror/Shared/**
+      - scripts/select_ios_simulator.py
+      - .github/workflows/mirror-ios.yml
+  pull_request:
+    paths:
+      - Mirror/iOS/**
+      - Mirror/Shared/**
+      - scripts/select_ios_simulator.py
+      - .github/workflows/mirror-ios.yml
+  # Release tags are lightweight, so `git push --follow-tags` does not push them and
+  # `gh release create` makes them on GitHub. That sends no tag push event.
+  release:
+    types:
+      - published
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  # The project needs no submodule, GhosttyKit, CLI, or Swift package, so this job does not use
+  # setup-macos. It also must not save the setup-macos caches, or it would take the cache keys
+  # of the Mac app job.
+  mirror-ios:
+    runs-on: macos-26
+    timeout-minutes: 20
+    permissions:
+      contents: read
+    env:
+      MISE_HTTP_TIMEOUT: 120
+      MISE_GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      # Install only the tools that the iOS mirror targets use.
+      MISE_EXEC_AUTO_INSTALL: false
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
+    steps:
+      - uses: actions/checkout@v6
+      - name: Install Tuist and xcsift
+        run: |
+          brew install mise
+          mise install tuist github:ldomaradzki/xcsift
+      - name: Test iOS mirror
+        run: make test-mirror-ios-unit
+      - name: Upload xcresult bundle and log (on failure)
+        # A job that reaches its timeout is cancelled, and its partial results are still useful.
+        if: failure() || cancelled()
+        uses: actions/upload-artifact@v4
+        with:
+          name: mirror-ios-xcresult-${{ github.run_id }}-${{ github.run_attempt }}
+          path: |
+            build/test-results/mirror-ios-unit.xcresult
+            build/test-results/mirror-ios-unit.xcresult.log
+          if-no-files-found: ignore
+          retention-days: 7
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 306e7f23b..272773276 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,10 +1,20 @@
 name: test
 
+# The Mac app. The mirror clients have their own workflows, and a change to only those
+# clients does not run this one.
 on:
   push:
     branches:
       - main
+    paths-ignore:
+      - Mirror/iOS/**
+      - Mirror/Android/**
+      - .github/workflows/mirror-*.yml
   pull_request:
+    paths-ignore:
+      - Mirror/iOS/**
+      - Mirror/Android/**
+      - .github/workflows/mirror-*.yml
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -28,8 +38,6 @@ jobs:
         with:
           submodules: recursive
       - uses: ./.github/actions/setup-macos
-      - run: make lint
-      - run: make check-localization
       - name: Stage debug app resources
         run: make embed-cli-debug embed-docs embed-skills
       - name: Generate workspace
@@ -74,18 +82,19 @@ jobs:
           # SwiftPM serializes access to .build; keep its checks in one branch.
           run_task cli-tests make test-cli-smoke test-cli-unit test-cli-integration &
           pid_cli=$!
-          run_task scripts make test-scripts &
-          pid_scripts=$!
+          # Lint and the localization check need no build, so they run beside it.
+          run_task checks make lint check-localization test-scripts &
+          pid_checks=$!
 
           failed=0
           wait "$pid_app" || failed=1
           wait "$pid_cli" || failed=1
-          wait "$pid_scripts" || failed=1
+          wait "$pid_checks" || failed=1
           {
             printf '## Build and test wall time\n\n| Task | Seconds | Exit status |\n| --- | ---: | ---: |\n'
             cat build/ci-logs/*.timing
             printf '\nTasks run in parallel; their times must not be added.\n\n'
-            python3 scripts/summarize-xcode-build.py build/test-results/*.build.json
+            python3 scripts/summarize-xcode-build.py build/test-results/*.build.json build/test-results/*.action.json
           } >> "$GITHUB_STEP_SUMMARY"
           exit "$failed"
       - name: Collect mirror diagnostics
@@ -100,6 +109,7 @@ jobs:
         run: |
           python3 scripts/ci-source-mtimes.py save
           python3 scripts/ci-source-mtimes.py save --scope app --manifest "$PROWL_DERIVED_DATA_PATH/source-times.json"
+      - uses: ./.github/actions/save-macos-caches
       - name: Upload build and test logs
         if: always()
         uses: actions/upload-artifact@v4
@@ -109,6 +119,7 @@ jobs:
             build/ci-logs/
             build/test-results/*.log
             build/test-results/*.build.json
+            build/test-results/*.action.json
           if-no-files-found: ignore
           retention-days: 7
       - name: Upload xcresult bundle (on failure)
@@ -119,59 +130,3 @@ jobs:
           path: build/test-results/**/*.xcresult
           if-no-files-found: ignore
           retention-days: 7
-
-  # Runs in parallel with `build`, one job for each simulator form factor. The iOS mirror
-  # project needs no submodule, GhosttyKit, CLI, or Swift package, so this job does not use
-  # setup-macos. It also must not save the setup-macos caches: this job ends first and would
-  # take the cache keys of `build`.
-  ios-mirror:
-    name: ios-mirror (${{ matrix.form-factor }})
-    runs-on: macos-26
-    timeout-minutes: 30
-    permissions:
-      contents: read
-    strategy:
-      fail-fast: false
-      matrix:
-        form-factor: [ipad, iphone]
-    env:
-      MISE_HTTP_TIMEOUT: 120
-      MISE_GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      # Install only the tools that the iOS mirror targets use.
-      MISE_EXEC_AUTO_INSTALL: false
-      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
-    steps:
-      - uses: actions/checkout@v6
-      - name: Install Tuist and xcsift
-        run: |
-          brew install mise
-          mise install tuist github:ldomaradzki/xcsift
-      - name: Test iOS mirror
-        run: make test-mirror-ios-${{ matrix.form-factor }}
-      - name: Upload xcresult bundle (on failure)
-        if: failure()
-        uses: actions/upload-artifact@v4
-        with:
-          name: ios-mirror-${{ matrix.form-factor }}-xcresult-${{ github.run_id }}-${{ github.run_attempt }}
-          path: build/test-results/mirror-ios-${{ matrix.form-factor }}.xcresult
-          if-no-files-found: ignore
-          retention-days: 7
-
-  android-mirror:
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
-    permissions:
-      contents: read
-    steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-java@v6
-        with:
-          distribution: temurin
-          java-version: '17'
-          cache: gradle
-      - uses: android-actions/setup-android@v4
-      - name: Install Android SDK 34
-        run: sdkmanager 'platforms;android-34' 'build-tools;34.0.0'
-      - name: Build and test Android mirror
-        working-directory: Mirror/Android
-        run: ./gradlew --no-daemon :app:assembleDebug :app:testDebugUnitTest :app:lintDebug
diff --git a/AGENTS.md b/AGENTS.md
index b52670c31..3fb42fe86 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -14,7 +14,8 @@ make format                      # Run full-tree swift-format cleanup
 make lint                        # Run swiftlint only
 make check                       # Run changed-file format, swift-format lint, swiftlint, and the string catalog check
 make audit-localization          # Release check of the string catalog and unlocalized UI copy (see the sync-l10n skill)
-make test                        # Run all tests
+make test                        # Run the Mac app tests
+make test-all                    # Run every test suite: scripts, CLI, Mac app, iOS mirror (unit and UI), Android mirror
 make benchmark-build             # Benchmark CI-like clean/warm-CAS build and test time
 make bench                       # Run performance benchmarks with -O; append absolute medians to ~/Library/Logs/Prowl/measurements/bench/
 make measure-cpu                 # Steady-state CPU + per-symbol attribution of the running Prowl Debug app
diff --git a/Makefile b/Makefile
index ba1180463..b11c084dd 100644
--- a/Makefile
+++ b/Makefile
@@ -26,18 +26,9 @@ APP_SCHEME := Prowl
 TEST_TARGET := ProwlTests
 IOS_MIRROR_PROJECT := $(CURRENT_MAKEFILE_DIR)/Mirror/iOS/ProwlMirror-iOS.xcodeproj
 IOS_MIRROR_SCHEME := ProwlMirror-iOS
-# Regular expressions for the full simulator name. Each Xcode release renames the models,
+# Regular expression for the full simulator name. Each Xcode release renames the models,
 # so scripts/select_ios_simulator.py uses the newest match on the newest supported runtime.
-IOS_MIRROR_IPAD_SIMULATOR_PATTERN ?= iPad Pro 11-inch \(M[0-9]+\)
-IOS_MIRROR_IPHONE_SIMULATOR_PATTERN ?= iPhone [0-9]+ Pro
-IOS_MIRROR_IPHONE_ONLY_TESTS := \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testClearingBothPairingHalvesAllowsCredentialReconnect \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testHostBoundariesDisableOnlyTheReachedDirection \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testRemoteScrollAlwaysRevealsTheTopWhileInteriorDragStaysLocal \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testRemoteScrollButtonsLeaveLocalGesturesAndHistoryUnchanged \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testRemoteScrollShowsLoadingAndKeepsHistoryIndependent \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testSelectingTextDoesNotScrollTheHost \
-	ProwlMirror-iOSUITests/ProwlMirror_iOSUITests/testPhoneStartsInDetailAndCanAddConnection
+IOS_MIRROR_SIMULATOR_PATTERN ?= iPad Pro 11-inch \(M[0-9]+\)
 XCODE_CONFIG_DIR := $(APP_DIR)/Config
 VERSION_XCCONFIG := $(XCODE_CONFIG_DIR)/Version.xcconfig
 TUIST_STAMP := $(CURRENT_MAKEFILE_DIR)/.tuist_generated_stamp
@@ -100,7 +91,7 @@ TEST_SIGNING_ARGS := CODE_SIGNING_ALLOWED=NO CODE_SIGNING_REQUIRED=NO CODE_SIGN_
 endif
 
 .DEFAULT_GOAL := help
-.PHONY: build-ghostty-xcframework ensure-ghostty sync-ghostty _record-ghostty-hash generate ensure-project ensure-mirror-ios-project build-app build-cli build-cli-release embed-cli-debug embed-cli embed-docs embed-skills run-app install-dev-build install-release archive export-archive format format-changed format-lint lint check test test-app test-mirror-ios test-mirror-ios-ipad test-mirror-ios-iphone test-scripts test-cli-smoke test-cli-unit test-cli-integration benchmark-build bump-version log-stream agent-versions
+.PHONY: build-ghostty-xcframework ensure-ghostty sync-ghostty _record-ghostty-hash generate ensure-project ensure-mirror-ios-project build-app build-cli build-cli-release embed-cli-debug embed-cli embed-docs embed-skills run-app install-dev-build install-release archive export-archive format format-changed format-lint lint check test test-all test-app test-mirror-ios test-mirror-ios-unit test-mirror-android test-scripts test-cli-smoke test-cli-unit test-cli-integration benchmark-build bump-version log-stream agent-versions
 .PHONY: test-agent-contracts _test-agent-contract-codex _test-agent-contract-export
 
 help:  # Display this help.
@@ -419,34 +410,50 @@ export-archive: # Export xarchive
 
 test: ensure-ghostty embed-cli-debug embed-docs embed-skills test-app
 
+# Recipe lines, not prerequisites, so that `make -j` cannot start two xcodebuild runs: a second
+# `xcodebuild test` in the same checkout can hang. The quick suites run first.
+test-all: # Run every test suite: scripts, CLI, Mac app, iOS mirror (unit and UI), Android mirror
+	$(MAKE) test-scripts
+	$(MAKE) test-cli-unit
+	$(MAKE) test-cli-smoke
+	$(MAKE) test-cli-integration
+	$(MAKE) test
+	$(MAKE) test-mirror-ios
+	$(MAKE) test-mirror-android
+
 # Internal: generate only the iOS mirror project. It has no package and does not need the
 # Mac app's build inputs (GhosttyKit, CLI, bundled resources), so the CI job can skip them.
 ensure-mirror-ios-project:
 	@cd "$(CURRENT_MAKEFILE_DIR)" && mise exec -- tuist generate --path Mirror/iOS --no-open
 
-# Run iOS mirror tests on one simulator form factor.
-# $(1): result bundle name, $(2): simulator name pattern, $(3): test selection arguments
+# Run iOS mirror tests on the iPad simulator.
+# $(1): result bundle name, $(2): test selection arguments
+# The UI tests take minutes and xcsift reports only at the end, so a heartbeat on stderr shows
+# progress, and the raw log stays next to the result bundle. The result bundle keeps failures and
+# screenshots; the simulator diagnostics collection can wait 10 minutes for a response, so it is off.
 define run_mirror_ios_tests
 @set -euo pipefail; \
 result_bundle="$(CURRENT_MAKEFILE_DIR)/build/test-results/$(1).xcresult"; \
 mkdir -p "$${result_bundle%/*}"; \
-destination="$$(python3 "$(CURRENT_MAKEFILE_DIR)/scripts/select_ios_simulator.py" "$(2)")"; \
+destination="$$(python3 "$(CURRENT_MAKEFILE_DIR)/scripts/select_ios_simulator.py" "$(IOS_MIRROR_SIMULATOR_PATTERN)")"; \
 rm -rf "$$result_bundle"; \
 xcodebuild test -project "$(IOS_MIRROR_PROJECT)" -scheme "$(IOS_MIRROR_SCHEME)" \
 	-destination "$$destination" -resultBundlePath "$$result_bundle" -parallel-testing-enabled NO \
-	$(3) 2>&1 | mise exec -- xcsift -w --format toon
+	-collect-test-diagnostics never \
+	$(2) 2>&1 | tee "$$result_bundle.log" \
+	| tee >(PROWL_TEST_PROGRESS_LABEL=$(1) PROWL_TEST_PROGRESS_INTERVAL=5 \
+		awk -f "$(CURRENT_MAKEFILE_DIR)/scripts/test-progress.awk" >&2) \
+	| mise exec -- xcsift -w --format toon
 endef
 
-test-mirror-ios: test-mirror-ios-ipad test-mirror-ios-iphone # Run iOS mirror unit/UI tests on their matching simulator form factors
+test-mirror-ios: ensure-mirror-ios-project # Run the iOS mirror unit and UI tests
+	$(call run_mirror_ios_tests,mirror-ios,-only-testing:ProwlMirror-iOSTests -only-testing:ProwlMirror-iOSUITests)
 
-test-mirror-ios-ipad: ensure-mirror-ios-project # Run the iOS mirror unit tests and the iPad UI tests
-	$(call run_mirror_ios_tests,mirror-ios-ipad,$(IOS_MIRROR_IPAD_SIMULATOR_PATTERN),\
-		-only-testing:ProwlMirror-iOSTests -only-testing:ProwlMirror-iOSUITests \
-		$(foreach test,$(IOS_MIRROR_IPHONE_ONLY_TESTS),-skip-testing:$(test)))
+test-mirror-ios-unit: ensure-mirror-ios-project # Run the iOS mirror unit tests (CI runs only these)
+	$(call run_mirror_ios_tests,mirror-ios-unit,-only-testing:ProwlMirror-iOSTests)
 
-test-mirror-ios-iphone: ensure-mirror-ios-project # Run the iOS mirror UI tests that need an iPhone
-	$(call run_mirror_ios_tests,mirror-ios-iphone,$(IOS_MIRROR_IPHONE_SIMULATOR_PATTERN),\
-		$(foreach test,$(IOS_MIRROR_IPHONE_ONLY_TESTS),-only-testing:$(test)))
+test-mirror-android: # Build, unit test and lint the Android mirror (needs JDK 17 and Android SDK 34)
+	cd "$(CURRENT_MAKEFILE_DIR)/Mirror/Android" && ./gradlew :app:assembleDebug :app:testDebugUnitTest :app:lintDebug
 
 test-scripts: # Run tests for the repository's scripts
 	@python3 -m unittest discover -s "$(CURRENT_MAKEFILE_DIR)/scripts" -p 'test_*.py'
@@ -474,6 +481,10 @@ test-app: ensure-ghostty ensure-project # Run app/unit tests via xcodebuild
 			xcrun xcresulttool get log --path "$$result_bundle" --type build --compact > "$$result_bundle.build.json" \
 				|| echo "warning: could not export Xcode build metrics" >&2; \
 		fi; \
+		if [ -d "$$result_bundle" ]; then \
+			xcrun xcresulttool get log --path "$$result_bundle" --type action --compact > "$$result_bundle.action.json" \
+				|| echo "warning: could not export the Xcode test action log" >&2; \
+		fi; \
 		if [ "$$xcodebuild_status" -ne 0 ]; then \
 			bash "$(CURRENT_MAKEFILE_DIR)/scripts/print-xcresult-failures.sh" "$$result_bundle" || true; \
 			return "$$xcodebuild_status"; \
diff --git a/Mirror/Android/README.md b/Mirror/Android/README.md
index b7a846b83..855a5e79a 100644
--- a/Mirror/Android/README.md
+++ b/Mirror/Android/README.md
@@ -64,6 +64,8 @@ Android Studio's bundled JBR or JDK 17 with an installed Android SDK 34. Set
 
     ./gradlew :app:assembleDebug :app:testDebugUnitTest :app:lintDebug
 
+From the repository root, `make test-mirror-android` runs the same tasks.
+
 APK: `app/build/outputs/apk/debug/app-debug.apk`.
 With an available emulator/device:
 
diff --git a/Mirror/iOS/ProwlMirror-iOS/ContentView.swift b/Mirror/iOS/ProwlMirror-iOS/ContentView.swift
index 978db87bf..5d6f3c7e0 100644
--- a/Mirror/iOS/ProwlMirror-iOS/ContentView.swift
+++ b/Mirror/iOS/ProwlMirror-iOS/ContentView.swift
@@ -6,13 +6,21 @@ struct ContentView: View {
   @State private var sessions: [MirrorSession] = []
   @State private var selectedID: UUID?
   @State private var showsConnection = false
-  @State private var columns: NavigationSplitViewVisibility =
-    UIDevice.current.userInterfaceIdiom == .phone ? .detailOnly : .all
-  @State private var compactColumn: NavigationSplitViewColumn =
-    UIDevice.current.userInterfaceIdiom == .phone ? .detail : .sidebar
+  @State private var columns: NavigationSplitViewVisibility
+  @State private var compactColumn: NavigationSplitViewColumn
   @State private var wasBackgrounded = false
 
+  /// iPhone starts on the detail column with the session list hidden; larger devices show both.
+  static func initialLayout(for idiom: UIUserInterfaceIdiom) -> (
+    columns: NavigationSplitViewVisibility, compactColumn: NavigationSplitViewColumn
+  ) {
+    idiom == .phone ? (.detailOnly, .detail) : (.all, .sidebar)
+  }
+
   init() {
+    let layout = Self.initialLayout(for: UIDevice.current.userInterfaceIdiom)
+    _columns = State(initialValue: layout.columns)
+    _compactColumn = State(initialValue: layout.compactColumn)
     #if DEBUG
       if CommandLine.arguments.contains("--mirror-ui-fixture") {
         let multiple = CommandLine.arguments.contains("--mirror-ui-multiple-fixtures")
@@ -279,16 +287,26 @@ private struct AddConnectionView: View {
   }
 }
 
+/// The row tops and the visible top of the live reader. It is not observable: it changes on every
+/// scroll, and no view shows it.
+private final class MirrorLiveReadingLayout {
+  var rowTops: [MirrorDocument.Row.ID: CGFloat] = [:]
+  var visibleTop: CGFloat = 0
+}
+
 private struct MirrorReadingView: View {
   @Bindable var session: MirrorSession
   @State private var showsConnectionEditor = false
-  @State private var position: ScrollPosition
-  @State private var observedInitialPosition = false
+  @State private var position = ScrollPosition(edge: .top)
+  @State private var layout = MirrorLiveReadingLayout()
+  /// The anchor to restore when the live reader appears. While it is set, scrolling does not
+  /// replace the stored anchor.
+  @State private var restoring: MirrorReadingAnchor?
   @State private var isEditing = false
 
   init(session: MirrorSession) {
     self.session = session
-    _position = State(initialValue: ScrollPosition(y: session.liveReadingOffset))
+    _restoring = State(initialValue: session.liveReadingAnchor)
   }
 
   var body: some View {
@@ -331,37 +349,42 @@ private struct MirrorReadingView: View {
         ScrollViewReader { proxy in
           ScrollView {
             VStack(alignment: .leading, spacing: 12) {
-              MirrorDocumentView(text: session.text)
+              MirrorDocumentView(text: session.text, onRowTop: rowTopChanged)
                 .frame(maxWidth: .infinity, alignment: .leading)
                 .accessibilityIdentifier("mirror-live-text")
               Color.clear.frame(height: 1).id("latest")
             }
             .padding()
+            .coordinateSpace(MirrorDocumentView.rowSpace)
           }
           .scrollPosition($position)
           .accessibilityIdentifier("mirror-live-scroll")
-          .onDisappear { observedInitialPosition = false }
+          .onDisappear { restoring = session.liveReadingAnchor }
           .onAppear {
             if session.followsLatest {
+              restoring = nil
               position.scrollTo(edge: .bottom)
-            } else {
-              position.scrollTo(y: session.liveReadingOffset)
+            } else if let restoring {
+              restore(restoring, with: proxy)
             }
           }
           .onScrollGeometryChange(for: CGFloat.self) { geometry in
             max(0, geometry.contentOffset.y + geometry.contentInsets.top)
-          } action: { _, offset in
-            if observedInitialPosition { session.liveReadingOffset = offset }
-            observedInitialPosition = true
+          } action: { _, top in
+            layout.visibleTop = top
+            storeAnchor()
           }
           .onScrollPhaseChange { _, phase in
-            if phase == .interacting { session.followsLatest = false }
+            guard phase == .interacting else { return }
+            session.followsLatest = false
+            restoring = nil
           }
           .onChange(of: session.revision) { _, _ in
             if session.followsLatest { proxy.scrollTo("latest", anchor: .bottom) }
           }
           .onChange(of: session.completedScroll) { _, completion in
             guard completion != nil else { return }
+            restoring = nil
             position.scrollTo(edge: .top)
           }
           .safeAreaInset(edge: .top) {
@@ -470,6 +493,38 @@ private struct MirrorReadingView: View {
       }
     }
   }
+
+  private func restore(_ anchor: MirrorReadingAnchor, with proxy: ScrollViewProxy) {
+    if let top = layout.rowTops[anchor.row] {
+      restoring = nil
+      position.scrollTo(y: top + anchor.offset)
+    } else if MirrorDocument(session.text).rows.contains(where: { $0.id == anchor.row }) {
+      // Lay out the anchor row first. `rowTopChanged` then applies the offset in the row.
+      proxy.scrollTo(anchor.row, anchor: .top)
+    } else {
+      restoring = nil
+      position.scrollTo(edge: .bottom)
+    }
+  }
+
+  private func rowTopChanged(_ row: MirrorDocument.Row.ID, _ top: CGFloat?) {
+    layout.rowTops[row] = top
+    guard let top else { return }
+    if let anchor = restoring {
+      guard anchor.row == row else { return }
+      restoring = nil
+      position.scrollTo(y: top + anchor.offset)
+    } else {
+      storeAnchor()
+    }
+  }
+
+  private func storeAnchor() {
+    guard restoring == nil,
+      let anchor = MirrorReadingAnchor(top: layout.visibleTop, rowTops: layout.rowTops)
+    else { return }
+    session.liveReadingAnchor = anchor
+  }
 }
 
 private struct MirrorConnectionEditor: View {
@@ -551,18 +606,21 @@ private struct MirrorHistoryView: View {
       .font(.caption).foregroundStyle(.secondary)
       ScrollViewReader { proxy in
         ScrollView {
-          LazyVStack(alignment: .leading) {
+          VStack(alignment: .leading) {
             Button("Load Earlier 200 Lines") { session.loadHistory() }
               .disabled(
                 session.historyOffset == 0 || session.isLoadingHistory || session.status != .live)
-            ForEach(
-              session.historyOffset..<(session.historyOffset + session.historyLines.count),
-              id: \.self
-            ) { index in
-              let line = session.historyLines[index - session.historyOffset]
-              Text(line.isEmpty ? " " : line).textSelection(.enabled)
-                .frame(maxWidth: .infinity, alignment: .leading)
-                .id(index)
+            // iOS 27 sends no taps to a button in the same stack as selectable text rows.
+            LazyVStack(alignment: .leading) {
+              ForEach(
+                session.historyOffset..<(session.historyOffset + session.historyLines.count),
+                id: \.self
+              ) { index in
+                let line = session.historyLines[index - session.historyOffset]
+                Text(line.isEmpty ? " " : line).textSelection(.enabled)
+                  .frame(maxWidth: .infinity, alignment: .leading)
+                  .id(index)
+              }
             }
           }
         }
diff --git a/Mirror/iOS/ProwlMirror-iOS/Features/Composer/MirrorComposer.swift b/Mirror/iOS/ProwlMirror-iOS/Features/Composer/MirrorComposer.swift
index 9ad502447..e42e45f8d 100644
--- a/Mirror/iOS/ProwlMirror-iOS/Features/Composer/MirrorComposer.swift
+++ b/Mirror/iOS/ProwlMirror-iOS/Features/Composer/MirrorComposer.swift
@@ -29,7 +29,7 @@ struct MirrorComposer: UIViewRepresentable {
     }
     view.canSubmit = session.canSubmit
     if !view.canSubmit { view.gesture.cancel() }
-    if !isEditing, view.isFirstResponder { view.resignFirstResponder() }
+    if !isEditing, view.isFirstResponder { _ = view.resignFirstResponder() }
   }
 
   func sizeThatFits(_ proposal: ProposedViewSize, uiView: ComposerTextView, context: Context)
diff --git a/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocument.swift b/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocument.swift
index f6d25fc70..49d93017b 100644
--- a/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocument.swift
+++ b/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocument.swift
@@ -19,8 +19,34 @@ nonisolated struct MirrorDocument {
     }
   }
 
+  /// One item of the reading layout and a scroll anchor: a code or table block, a text block
+  /// that fits in one layout chunk, or one chunk of a longer text block.
+  struct Row: Identifiable {
+    struct ID: Hashable, Comparable {
+      let block: Int
+      let chunk: Int
+
+      static func < (lhs: ID, rhs: ID) -> Bool { (lhs.block, lhs.chunk) < (rhs.block, rhs.chunk) }
+    }
+
+    let id: ID
+    let block: Block
+    /// The chunk to show, or nil to show the whole block.
+    let chunk: MirrorTextLayout.Chunk?
+  }
+
   let blocks: [Block]
 
+  var rows: [Row] {
+    blocks.flatMap { block -> [Row] in
+      let whole = [Row(id: .init(block: block.id, chunk: 0), block: block, chunk: nil)]
+      guard case .text(_, let content) = block else { return whole }
+      let chunks = MirrorTextLayout.chunks(content)
+      guard chunks.count > 1 else { return whole }
+      return chunks.map { Row(id: .init(block: block.id, chunk: $0.id), block: block, chunk: $0) }
+    }
+  }
+
   init(_ text: String) {
     let lines = text.components(separatedBy: "\n")
     var result: [Block] = []
diff --git a/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocumentView.swift b/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocumentView.swift
index ed4247768..351cea6a5 100644
--- a/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocumentView.swift
+++ b/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorDocumentView.swift
@@ -1,36 +1,29 @@
 import SwiftUI
 
 struct MirrorDocumentView: View {
+  /// The coordinate space of the row tops. Apply it to the scroll content.
+  nonisolated static var rowSpace: NamedCoordinateSpace { .named("MirrorDocumentView.rows") }
+
   let text: String
+  /// Receives the top of each row in `rowSpace` when the row is laid out, and nil when it leaves
+  /// the layout.
+  var onRowTop: ((MirrorDocument.Row.ID, CGFloat?) -> Void)?
   @State private var expanded: MirrorDocument.Block?
 
   var body: some View {
-    LazyVStack(alignment: .leading, spacing: 12) {
-      ForEach(MirrorDocument(text).blocks) { block in
-        switch block {
-        case .text(_, let content):
-          textBlock(content)
-        case .code(_, let language, let code):
-          VStack(alignment: .leading, spacing: 8) {
-            HStack {
-              Text(language.isEmpty ? "Code" : language).font(.caption).foregroundStyle(.secondary)
-              Spacer()
-              Button("Expand") { expanded = block }
-            }
-            Text(code).font(.body.monospaced()).lineLimit(6).textSelection(.enabled)
-          }
-          .padding().background(.quaternary, in: RoundedRectangle(cornerRadius: 12))
-        case .table(_, _, let rows):
-          VStack(alignment: .leading, spacing: 8) {
-            HStack {
-              Text("Table · \(rows.count - 1) rows").font(.caption).foregroundStyle(.secondary)
-              Spacer()
-              Button("Expand") { expanded = block }
-            }
-            ScrollView(.horizontal) { table(Array(rows.prefix(5))) }
+    // One flat lazy stack: each chunk of a long text block is a row, so a reading position can
+    // anchor to the text near the top of the visible area.
+    LazyVStack(alignment: .leading, spacing: 0) {
+      ForEach(MirrorDocument(text).rows) { row in
+        rowContent(row)
+          .padding(.top, row.id.chunk == 0 && row.id.block > 0 ? 12 : 0)
+          .id(row.id)
+          .onGeometryChange(for: CGFloat.self) {
+            $0.frame(in: Self.rowSpace).minY
+          } action: { top in
+            onRowTop?(row.id, top)
           }
-          .padding().background(.quaternary, in: RoundedRectangle(cornerRadius: 12))
-        }
+          .onDisappear { onRowTop?(row.id, nil) }
       }
     }
     .sheet(item: $expanded) { block in
@@ -45,31 +38,50 @@ struct MirrorDocumentView: View {
     }
   }
 
-  private func renderInline(_ text: String) -> AttributedString {
-    (try? AttributedString(
-      markdown: text, options: .init(interpretedSyntax: .inlineOnlyPreservingWhitespace)))
-      ?? AttributedString(text)
-  }
-
   @ViewBuilder
-  private func textBlock(_ content: String) -> some View {
-    let chunks = MirrorTextLayout.chunks(content)
-    if chunks.count == 1 {
-      Text(renderInline(content)).textSelection(.enabled)
-    } else {
-      LazyVStack(alignment: .leading, spacing: 0) {
-        ForEach(chunks) { chunk in
-          Text(verbatim: chunk.display)
-            .textSelection(.enabled)
-            .frame(maxWidth: .infinity, alignment: .leading)
+  private func rowContent(_ row: MirrorDocument.Row) -> some View {
+    let block = row.block
+    switch block {
+    case .text(_, let content):
+      if let chunk = row.chunk {
+        Text(verbatim: chunk.display)
+          .textSelection(.enabled)
+          .frame(maxWidth: .infinity, alignment: .leading)
+          .contextMenu {
+            Button("Copy Full Text Block") { UIPasteboard.general.string = content }
+          }
+      } else {
+        Text(renderInline(content)).textSelection(.enabled)
+      }
+    case .code(_, let language, let code):
+      VStack(alignment: .leading, spacing: 8) {
+        HStack {
+          Text(language.isEmpty ? "Code" : language).font(.caption).foregroundStyle(.secondary)
+          Spacer()
+          Button("Expand") { expanded = block }
         }
+        Text(code).font(.body.monospaced()).lineLimit(6).textSelection(.enabled)
       }
-      .contextMenu {
-        Button("Copy Full Text Block") { UIPasteboard.general.string = content }
+      .padding().background(.quaternary, in: RoundedRectangle(cornerRadius: 12))
+    case .table(_, _, let rows):
+      VStack(alignment: .leading, spacing: 8) {
+        HStack {
+          Text("Table · \(rows.count - 1) rows").font(.caption).foregroundStyle(.secondary)
+          Spacer()
+          Button("Expand") { expanded = block }
+        }
+        ScrollView(.horizontal) { table(Array(rows.prefix(5))) }
       }
+      .padding().background(.quaternary, in: RoundedRectangle(cornerRadius: 12))
     }
   }
 
+  private func renderInline(_ text: String) -> AttributedString {
+    (try? AttributedString(
+      markdown: text, options: .init(interpretedSyntax: .inlineOnlyPreservingWhitespace)))
+      ?? AttributedString(text)
+  }
+
   private func table(_ rows: [[String]]) -> some View {
     Grid(alignment: .leading, horizontalSpacing: 18, verticalSpacing: 10) {
       ForEach(Array(rows.enumerated()), id: \.offset) { index, cells in
diff --git a/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorReadingAnchor.swift b/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorReadingAnchor.swift
new file mode 100644
index 000000000..5cc48bd61
--- /dev/null
+++ b/Mirror/iOS/ProwlMirror-iOS/Features/Reading/MirrorReadingAnchor.swift
@@ -0,0 +1,22 @@
+import CoreGraphics
+
+/// A live reading position: a document row and the distance from the top of that row to the
+/// top of the visible area. When a pane switch creates the reading view again, `LazyVStack`
+/// estimates the heights of the rows that it has not laid out, so an absolute scroll offset
+/// does not show the same text again.
+nonisolated struct MirrorReadingAnchor: Equatable {
+  let row: MirrorDocument.Row.ID
+  let offset: CGFloat
+}
+
+extension MirrorReadingAnchor {
+  /// Makes the anchor for the visible top `top` from the content tops of the rows that are laid
+  /// out: the last row that starts at or above `top`, else the first row below it.
+  nonisolated init?(top: CGFloat, rowTops: [MirrorDocument.Row.ID: CGFloat]) {
+    let rows = rowTops.map { ($0.value, $0.key) }
+    guard let (rowTop, row) = rows.filter({ $0.0 <= top }).max(by: <) ?? rows.min(by: <) else {
+      return nil
+    }
+    self.init(row: row, offset: top - rowTop)
+  }
+}
diff --git a/Mirror/iOS/ProwlMirror-iOS/Features/Sessions/MirrorSession.swift b/Mirror/iOS/ProwlMirror-iOS/Features/Sessions/MirrorSession.swift
index e22343f8e..82abee957 100644
--- a/Mirror/iOS/ProwlMirror-iOS/Features/Sessions/MirrorSession.swift
+++ b/Mirror/iOS/ProwlMirror-iOS/Features/Sessions/MirrorSession.swift
@@ -50,6 +50,7 @@ final class MirrorSession: Identifiable {
   @ObservationIgnored private var pendingCommand: PendingCommand?
   @ObservationIgnored private var commandTimeout: Task<Void, Never>?
   @ObservationIgnored private let clock: any Clock<Duration>
+  @ObservationIgnored private let scrollConfirmationTimeout: Duration
 
   private struct PendingCommand {
     let id: UUID
@@ -89,7 +90,9 @@ final class MirrorSession: Identifiable {
   private(set) var historyTruncated = false
   private(set) var isLoadingHistory = false
   var showsHistory = false
-  var liveReadingOffset: CGFloat = 0
+  /// The reading view writes it on every scroll and reads it only when it appears, so a change
+  /// must not update views.
+  @ObservationIgnored var liveReadingAnchor: MirrorReadingAnchor?
   var historyReadingOffset: CGFloat = 0
   @ObservationIgnored private var historyID: UUID?
   @ObservationIgnored private var historyBytes = 0
@@ -139,12 +142,14 @@ final class MirrorSession: Identifiable {
   init(
     configuration: MirrorSavedConnection,
     clock: any Clock<Duration> = ContinuousClock(),
+    scrollConfirmationTimeout: Duration = .seconds(5),
     makeTransport: @escaping (MirrorSavedConnection) throws -> any MirrorTransport = {
       configuration in
       MirrorRemoteConnection(configuration: configuration)
     }
   ) {
     self.clock = clock
+    self.scrollConfirmationTimeout = scrollConfirmationTimeout
     self.configuration = configuration
     self.makeTransport = makeTransport
   }
@@ -242,7 +247,7 @@ final class MirrorSession: Identifiable {
       text = ""
       revision = 0
       updatedAt = nil
-      liveReadingOffset = 0
+      liveReadingAnchor = nil
       historyReadingOffset = 0
       historyID = nil
       historyLines = []
@@ -439,8 +444,9 @@ final class MirrorSession: Identifiable {
     scrollError = nil
     followsLatest = false
     let clock = clock
+    let timeout = scrollConfirmationTimeout
     scrollTimeout = Task { [weak self] in
-      do { try await clock.sleep(for: .seconds(5)) } catch { return }
+      do { try await clock.sleep(for: timeout) } catch { return }
       guard self?.pendingScroll?.id == request.id else { return }
       self?.clearScroll()
       self?.scrollError = String(
diff --git a/Mirror/iOS/ProwlMirror-iOS/Infrastructure/MirrorUIFixture.swift b/Mirror/iOS/ProwlMirror-iOS/Infrastructure/MirrorUIFixture.swift
index 99801e8bf..172be77ba 100644
--- a/Mirror/iOS/ProwlMirror-iOS/Infrastructure/MirrorUIFixture.swift
+++ b/Mirror/iOS/ProwlMirror-iOS/Infrastructure/MirrorUIFixture.swift
@@ -28,11 +28,19 @@
       return try JSONDecoder().decode(MirrorJSON.self, from: Data(payload.utf8))
     }
 
+    /// With `--mirror-ui-scroll-hold-fixture`, the fixture Host confirms a scroll only when the UI
+    /// test posts this Darwin notification, so the test can check the loading state at any speed.
+    static let releaseScrollNotification = "com.awhisper.ProwlMirror-iOS.ui-fixture.release-scroll"
+    private static var holdsScroll: Bool {
+      CommandLine.arguments.contains("--mirror-ui-scroll-hold-fixture")
+    }
+
     static func session(name: String = "UI Fixture", longOutput: Bool = false) -> MirrorSession {
       let channel = Channel(name: name, longOutput: longOutput)
       let session = MirrorSession(
         configuration: .init(
           address: "127.0.0.1", port: 7880, pairingKey: ""),
+        scrollConfirmationTimeout: holdsScroll ? .seconds(120) : .seconds(5),
         makeTransport: { _ in channel })
       session.connect()
       session.select(channel.pane)
@@ -50,6 +58,20 @@
         pane = MirrorPaneDescriptor(
           id: UUID(), title: "\(name) · Codex", directory: "/fixture", busy: false,
           projectName: name, subtitle: "Codex · main")
+        if MirrorUIFixture.holdsScroll {
+          CFNotificationCenterAddObserver(
+            CFNotificationCenterGetDarwinNotifyCenter(), Unmanaged.passUnretained(self).toOpaque(),
+            { _, observer, _, _, _ in
+              guard let observer else { return }
+              let channel = Unmanaged<Channel>.fromOpaque(observer).takeUnretainedValue()
+              Task { @MainActor in channel.releaseHeldScrolls() }
+            },
+            MirrorUIFixture.releaseScrollNotification as CFString, nil, .deliverImmediately)
+        }
+      }
+      deinit {
+        CFNotificationCenterRemoveEveryObserver(
+          CFNotificationCenterGetDarwinNotifyCenter(), Unmanaged.passUnretained(self).toOpaque())
       }
       private let lease = UUID()
       private let run = UUID()
@@ -57,12 +79,12 @@
         text: (1...401).map { "Retained line \($0)" }.joined(separator: "\n"), truncated: true)
       private var sequence: UInt64 = 0
       private var scrollPage = 0
-      private var scrollTask: Task<Void, Never>?
+      private var heldScrolls: [MirrorMessage] = []
       private var includesScrollState = false
 
       func start() { onReady?() }
       func close(_ reason: String?) {
-        scrollTask?.cancel()
+        heldScrolls = []
         onClose?(reason)
       }
 
@@ -148,16 +170,19 @@
       }
 
       private func scroll(_ message: MirrorMessage) {
-        if CommandLine.arguments.contains("--mirror-ui-scroll-delay-fixture") {
-          scrollTask = Task { [weak self] in
-            do { try await ContinuousClock().sleep(for: .seconds(2)) } catch { return }
-            self?.completeScroll(message)
-          }
+        if MirrorUIFixture.holdsScroll {
+          heldScrolls.append(message)
         } else {
           completeScroll(message)
         }
       }
 
+      private func releaseHeldScrolls() {
+        let scrolls = heldScrolls
+        heldScrolls = []
+        scrolls.forEach(completeScroll)
+      }
+
       private func completeScroll(_ message: MirrorMessage) {
         guard let id = message.scrollRequestID, let direction = message.scrollDirection else { return }
         scrollPage += direction == .upward ? -1 : 1
diff --git a/Mirror/iOS/ProwlMirror-iOSTests/MirrorComposerTests.swift b/Mirror/iOS/ProwlMirror-iOSTests/MirrorComposerTests.swift
index 4aac713e2..718bd44d6 100644
--- a/Mirror/iOS/ProwlMirror-iOSTests/MirrorComposerTests.swift
+++ b/Mirror/iOS/ProwlMirror-iOSTests/MirrorComposerTests.swift
@@ -13,7 +13,7 @@ struct MirrorComposerTests {
     view.selectedRange = NSRange(location: 8, length: 0)
     var sends = 0
     view.onSubmit = { sends += 1 }
-    let press = ReturnPress()
+    let press = ReturnPress(key: ReturnKey())
     let event = KeyEvent()
     view.pressesBegan([press], with: event)
     #expect(view.text == "message\n\n")
@@ -57,8 +57,15 @@ struct MirrorComposerTests {
     override var characters: String { "\r" }
     override var charactersIgnoringModifiers: String { "\r" }
   }
+  /// `UIPress` is not isolated to the main actor, but `UIKey` is. The test makes the key on the
+  /// main actor, and `key` only returns it.
   private final class ReturnPress: UIPress {
-    override var key: UIKey? { ReturnKey() }
+    private let returnKey: UIKey
+    init(key: UIKey) {
+      returnKey = key
+      super.init()
+    }
+    override var key: UIKey? { returnKey }
   }
   private final class KeyEvent: UIPressesEvent {
     var time: TimeInterval = 0
diff --git a/Mirror/iOS/ProwlMirror-iOSTests/MirrorDocumentTests.swift b/Mirror/iOS/ProwlMirror-iOSTests/MirrorDocumentTests.swift
index 04c45eece..952e60fb1 100644
--- a/Mirror/iOS/ProwlMirror-iOSTests/MirrorDocumentTests.swift
+++ b/Mirror/iOS/ProwlMirror-iOSTests/MirrorDocumentTests.swift
@@ -22,4 +22,18 @@ struct MirrorDocumentTests {
     #expect(MirrorDocument("").blocks == [.text(0, "")])
     #expect(MirrorDocument("done").blocks == [.text(0, "done")])
   }
+
+  @Test func rowsKeepShortBlocksWholeAndSplitLongTextIntoChunks() {
+    let long = (1...40).map { "line \($0)" }.joined(separator: "\n")
+    let document = MirrorDocument("intro\n```\ncode\n```\n" + long)
+    #expect(
+      document.rows.map(\.id) == [
+        .init(block: 0, chunk: 0), .init(block: 1, chunk: 0), .init(block: 2, chunk: 0),
+        .init(block: 2, chunk: 1),
+      ])
+    #expect(document.rows[0].chunk == nil)
+    #expect(document.rows[1].chunk == nil)
+    #expect(document.rows[2...].map { $0.chunk?.raw ?? "" }.joined() == long)
+    #expect(document.rows[2...].allSatisfy { $0.block == document.blocks[2] })
+  }
 }
diff --git a/Mirror/iOS/ProwlMirror-iOSTests/MirrorInitialLayoutTests.swift b/Mirror/iOS/ProwlMirror-iOSTests/MirrorInitialLayoutTests.swift
new file mode 100644
index 000000000..cb1465319
--- /dev/null
+++ b/Mirror/iOS/ProwlMirror-iOSTests/MirrorInitialLayoutTests.swift
@@ -0,0 +1,21 @@
+import SwiftUI
+import Testing
+import UIKit
+
+@testable import ProwlMirror_iOS
+
+@MainActor
+struct MirrorInitialLayoutTests {
+  @Test func phoneStartsOnTheDetailColumnWithTheSessionListHidden() {
+    let layout = ContentView.initialLayout(for: .phone)
+    #expect(layout.columns == .detailOnly)
+    #expect(layout.compactColumn == .detail)
+  }
+
+  @Test(arguments: [UIUserInterfaceIdiom.pad, .mac])
+  func largerDevicesShowTheSessionList(_ idiom: UIUserInterfaceIdiom) {
+    let layout = ContentView.initialLayout(for: idiom)
+    #expect(layout.columns == .all)
+    #expect(layout.compactColumn == .sidebar)
+  }
+}
diff --git a/Mirror/iOS/ProwlMirror-iOSTests/MirrorReadingAnchorTests.swift b/Mirror/iOS/ProwlMirror-iOSTests/MirrorReadingAnchorTests.swift
new file mode 100644
index 000000000..ea3e05050
--- /dev/null
+++ b/Mirror/iOS/ProwlMirror-iOSTests/MirrorReadingAnchorTests.swift
@@ -0,0 +1,35 @@
+import CoreGraphics
+import Testing
+
+@testable import ProwlMirror_iOS
+
+struct MirrorReadingAnchorTests {
+  private let rowTops: [MirrorDocument.Row.ID: CGFloat] = [
+    .init(block: 0, chunk: 0): 16, .init(block: 1, chunk: 0): 120, .init(block: 1, chunk: 1): 400,
+  ]
+
+  @Test func anchorIsTheLastRowThatStartsAtOrAboveTheVisibleTop() {
+    #expect(
+      MirrorReadingAnchor(top: 250, rowTops: rowTops)
+        == .init(row: .init(block: 1, chunk: 0), offset: 130))
+    #expect(
+      MirrorReadingAnchor(top: 400, rowTops: rowTops)
+        == .init(row: .init(block: 1, chunk: 1), offset: 0))
+  }
+
+  @Test func anchorUsesTheFirstRowWhenNoRowStartsAboveTheVisibleTop() {
+    #expect(
+      MirrorReadingAnchor(top: 0, rowTops: rowTops)
+        == .init(row: .init(block: 0, chunk: 0), offset: -16))
+    #expect(MirrorReadingAnchor(top: 0, rowTops: [:]) == nil)
+  }
+
+  @Test func rowsWithTheSameTopUseTheLaterRow() {
+    let empty: [MirrorDocument.Row.ID: CGFloat] = [
+      .init(block: 0, chunk: 0): 16, .init(block: 1, chunk: 0): 16, .init(block: 2, chunk: 0): 16,
+    ]
+    #expect(
+      MirrorReadingAnchor(top: 20, rowTops: empty)
+        == .init(row: .init(block: 2, chunk: 0), offset: 4))
+  }
+}
diff --git a/Mirror/iOS/ProwlMirror-iOSTests/MirrorSessionTests.swift b/Mirror/iOS/ProwlMirror-iOSTests/MirrorSessionTests.swift
index 0aae13448..f9cbbca58 100644
--- a/Mirror/iOS/ProwlMirror-iOSTests/MirrorSessionTests.swift
+++ b/Mirror/iOS/ProwlMirror-iOSTests/MirrorSessionTests.swift
@@ -92,7 +92,7 @@ struct MirrorSessionTests {
       .textFrame(.init(sequence: 2, text: "new live", subscriptionID: lease)))
     #expect(session.historyLines == ["first", "last"])
     #expect(session.text == "new live")
-    session.liveReadingOffset = 300
+    session.liveReadingAnchor = .init(row: .init(block: 0, chunk: 0), offset: 300)
     session.historyReadingOffset = 200
     session.updateConnection(
       .init(
@@ -100,7 +100,7 @@ struct MirrorSessionTests {
         pairingKey: String(repeating: "a", count: 64)))
     #expect(session.historyLines.isEmpty)
     #expect(!session.showsHistory)
-    #expect(session.liveReadingOffset == 0)
+    #expect(session.liveReadingAnchor == nil)
     #expect(session.historyReadingOffset == 0)
   }
 
diff --git a/Mirror/iOS/ProwlMirror-iOSUITests/ProwlMirror_iOSUITests.swift b/Mirror/iOS/ProwlMirror-iOSUITests/ProwlMirror_iOSUITests.swift
index 621e37221..0ba1d1664 100644
--- a/Mirror/iOS/ProwlMirror-iOSUITests/ProwlMirror_iOSUITests.swift
+++ b/Mirror/iOS/ProwlMirror-iOSUITests/ProwlMirror_iOSUITests.swift
@@ -121,7 +121,7 @@ final class ProwlMirror_iOSUITests: XCTestCase {
   func testRemoteScrollShowsLoadingAndKeepsHistoryIndependent() {
     let app = XCUIApplication()
     app.launchArguments = [
-      "--mirror-ui-fixture", "--mirror-ui-scroll-fixture", "--mirror-ui-scroll-delay-fixture",
+      "--mirror-ui-fixture", "--mirror-ui-scroll-fixture", "--mirror-ui-scroll-hold-fixture",
     ]
     app.launch()
     XCUIDevice.shared.orientation = .portrait
@@ -137,13 +137,17 @@ final class ProwlMirror_iOSUITests: XCTestCase {
     attachment.name = "Remote scroll loading"
     attachment.lifetime = .keepAlways
     add(attachment)
+    releaseHeldScrolls()
     let olderPage = app.staticTexts.matching(NSPredicate(format: "label BEGINSWITH %@", "Remote page -1\n")).firstMatch
     XCTAssertTrue(olderPage.waitForExistence(timeout: 8))
     XCTAssertFalse(progress.exists)
     scrollDown.tap()
+    XCTAssertTrue(progress.waitForExistence(timeout: 5))
     app.buttons["History"].tap()
     XCTAssertTrue(app.staticTexts["Loaded lines 202–401"].waitForExistence(timeout: 5))
     XCTAssertFalse(scrollUp.exists)
+    // Host confirms the downward scroll while History is open.
+    releaseHeldScrolls()
     app.buttons["Load Earlier 200 Lines"].tap()
     XCTAssertTrue(app.staticTexts["Loaded lines 2–401"].waitForExistence(timeout: 5))
     app.buttons["Live Output"].tap()
@@ -249,20 +253,6 @@ final class ProwlMirror_iOSUITests: XCTestCase {
     XCTAssertTrue(app.staticTexts["created-mirror"].waitForExistence(timeout: 5))
   }
 
-  @MainActor
-  func testPhoneStartsInDetailAndCanAddConnection() throws {
-    try XCTSkipUnless(UIDevice.current.userInterfaceIdiom == .phone, "Phone navigation coverage")
-    let app = XCUIApplication()
-    app.launch()
-    XCUIDevice.shared.orientation = .portrait
-    XCTAssertTrue(app.staticTexts["Choose a Remote Pane"].waitForExistence(timeout: 10))
-    XCTAssertFalse(app.staticTexts["Connect to Prowl"].isHittable)
-    app.buttons["Add Remote Pane"].tap()
-    XCTAssertTrue(app.textFields["host-address"].waitForExistence(timeout: 5))
-    app.buttons["Cancel"].tap()
-    XCTAssertTrue(app.staticTexts["Choose a Remote Pane"].waitForExistence(timeout: 5))
-  }
-
   @MainActor
   func testSidebarClosesMirrorsWithOneClick() {
     let app = XCUIApplication()
@@ -535,4 +525,13 @@ final class ProwlMirror_iOSUITests: XCTestCase {
     app.buttons["Cancel"].tap()
     XCTAssertTrue(app.buttons["Add Remote Pane"].firstMatch.waitForExistence(timeout: 5))
   }
+
+  /// Makes the fixture Host confirm the scrolls that `--mirror-ui-scroll-hold-fixture` holds.
+  /// The name matches `MirrorUIFixture.releaseScrollNotification`.
+  private func releaseHeldScrolls() {
+    CFNotificationCenterPostNotification(
+      CFNotificationCenterGetDarwinNotifyCenter(),
+      CFNotificationName("com.awhisper.ProwlMirror-iOS.ui-fixture.release-scroll" as CFString), nil, nil,
+      true)
+  }
 }
diff --git a/Mirror/iOS/README.md b/Mirror/iOS/README.md
index 672c84a30..1a5639227 100644
--- a/Mirror/iOS/README.md
+++ b/Mirror/iOS/README.md
@@ -99,19 +99,19 @@ command correlation/routing, reading and keyboard behavior. The Host's real App
 target covers pairing, revocation, terminal capture and input protection; there is
 no copied Host implementation in this client's tests.
 
-Run the iOS mirror unit and UI suites on their matching simulator form factors:
+Run the iOS mirror unit and UI suites on an iPad simulator:
 
 ```bash
 make test-mirror-ios
 ```
 
 The target generates only this project, so it does not need the Mac app's build inputs.
-It runs the split-pane and composer tests on iPad (`make test-mirror-ios-ipad`), then the
-remote-scroll, pairing, and phone-navigation tests on iPhone (`make test-mirror-ios-iphone`).
-The UI suites take several minutes. It uses the newest iPad Pro 11-inch and iPhone Pro
-simulators on the newest runtime that the selected Xcode supports. To use other models,
-set `IOS_MIRROR_IPAD_SIMULATOR_PATTERN` or `IOS_MIRROR_IPHONE_SIMULATOR_PATTERN` to a
-regular expression for the full simulator name.
+The UI suite takes several minutes. `make test-mirror-ios-unit` runs only the unit tests.
+CI runs only the unit tests, and only when a pull request changes `Mirror/iOS/` or
+`Mirror/Shared/`, and for each published release. Run the UI suite locally before you merge changes to
+this client. The target uses the newest iPad Pro 11-inch simulator on the newest runtime that
+the selected Xcode supports. To use another model, set `IOS_MIRROR_SIMULATOR_PATTERN` to a
+regular expression for the full simulator name. The UI tests also pass on iPhone.
 
 DEBUG-only `--mirror-ui-fixture` and `--mirror-ui-launch-fixture` supply deterministic
 UI data without connecting to Host or starting an Agent. Component and socket tests
diff --git a/README.md b/README.md
index e3f7d5854..171131885 100644
--- a/README.md
+++ b/README.md
@@ -147,6 +147,7 @@ make format-changed        # Format changed Swift files only
 make format                # Full-tree Swift format cleanup
 make lint                  # SwiftLint only
 make test                  # Run app/unit tests
+make test-all              # Run every test suite, including the CLI and both mirror clients
 make log-stream            # Stream app logs (subsystem: com.onevcat.prowl)
 ```
 
diff --git a/docs-ai/016-dev-build-and-ci-workflow/000-plan.md b/docs-ai/016-dev-build-and-ci-workflow/000-plan.md
index bd274dea9..2e0c4728a 100644
--- a/docs-ai/016-dev-build-and-ci-workflow/000-plan.md
+++ b/docs-ai/016-dev-build-and-ci-workflow/000-plan.md
@@ -98,3 +98,7 @@ Anchor wave, all landed 2026-04-04/05:
   [006-ci-source-cache-reuse.md](006-ci-source-cache-reuse.md)
 - Updated 2026-09-06: App incremental-state reuse and measured module extraction — see
   [007-app-incremental-and-module-boundaries.md](007-app-incremental-and-module-boundaries.md)
+- Updated 2026-10-04: the CAS cache step used a path that never existed after 007; restore the
+  CAS from the newest App incremental entry on a miss, save large caches only from main, and
+  run the mirror client jobs only when they change (corrects 007's CAS note) — see
+  [008-cas-fallback-and-cache-scope.md](008-cas-fallback-and-cache-scope.md)
diff --git a/docs-ai/016-dev-build-and-ci-workflow/007-app-incremental-and-module-boundaries.md b/docs-ai/016-dev-build-and-ci-workflow/007-app-incremental-and-module-boundaries.md
index 36b2827c0..bf00fef6e 100644
--- a/docs-ai/016-dev-build-and-ci-workflow/007-app-incremental-and-module-boundaries.md
+++ b/docs-ai/016-dev-build-and-ci-workflow/007-app-incremental-and-module-boundaries.md
@@ -36,7 +36,9 @@ App state is cached at a fixed CI DerivedData path. Its restore prefix includes
 Xcode build, Ghostty revision, project/package/build configuration and tracked input paths.
 Added/deleted source or resource paths therefore start fresh instead of retaining stale
 products. CLI-owned Shared timestamps are excluded from App timestamp restoration. Content
-changes retain normal compiler/resource invalidation; the existing CAS remains available.
+changes retain normal compiler/resource invalidation. (Correction, 2026-10-04: the separate
+CAS cache step did not remain available. With the fixed DerivedData path the CAS moved into it,
+so that step cached a path that never existed; see [008](008-cas-fallback-and-cache-scope.md).)
 
 ## Verification
 
diff --git a/docs-ai/016-dev-build-and-ci-workflow/008-cas-fallback-and-cache-scope.md b/docs-ai/016-dev-build-and-ci-workflow/008-cas-fallback-and-cache-scope.md
new file mode 100644
index 000000000..ad20c14b2
--- /dev/null
+++ b/docs-ai/016-dev-build-and-ci-workflow/008-cas-fallback-and-cache-scope.md
@@ -0,0 +1,82 @@
+# 016.008 — CAS Fallback, Cache Save Scope and Mirror Jobs
+
+## Context
+
+In #851, a pull request that changed the Makefile and the test workflow spent about 10 minutes
+compiling the App (2,000+ compile steps) in the `build` job; the same job with a restored App
+incremental cache compiles in under 2 minutes. Three problems caused this or made it likely:
+
+- **The CAS cache was never used.** The `xcode-compilation-cache` step from
+  [005](005-build-test-time-optimization.md) cached
+  `~/Library/Developer/Xcode/DerivedData/CompilationCache.noindex`. Since
+  [007](007-app-incremental-and-module-boundaries.md) the App builds with
+  `-derivedDataPath build/ci-derived-data`, and Xcode then keeps the CAS at
+  `<derivedDataPath>/CompilationCache.noindex` (`COMPILATION_CACHE_CAS_PATH`). The cached
+  path never existed: every run logged "Cache not found", and no run saved an entry. A miss of
+  the strict App incremental key (changed build configuration, Makefile, workflow or tracked
+  file roster) therefore built without any compiler cache.
+- **Pull requests evicted the entries of main.** Every pull request run that changed sources
+  saved a new App incremental entry (about 930 MB) and CLI entry (about 670 MB). The repository
+  used 10.7 GB of its 10 GB quota, and least-recently-used eviction removes the main entries
+  that every pull request restores. Saving also added up to 53 s to pull request runs.
+- **Mirror client jobs ran for every change.** The iOS mirror UI suite took 11–20 minutes on
+  hosted runners for each pull request, including pull requests that changed only the Mac app.
+
+## Change
+
+- `.github/actions/setup-macos/action.yml` restores caches with `actions/cache/restore`.
+  The dead CAS step is removed. When the strict App incremental key finds nothing, the action
+  restores the newest App incremental entry for the same Xcode build and workspace, and keeps
+  only its `CompilationCache.noindex`. The build is clean (no stale products from a changed
+  file roster or configuration) but replays compiler outputs from the content-addressed cache.
+  This reuses existing entries and needs no more cache space.
+- `.github/actions/save-macos-caches/action.yml` saves the caches at the end of the job, after
+  the build input times. Only `main` saves the SwiftPM, CLI and App entries. Pull requests
+  still save the Mise and GhosttyKit entries, which are small and change rarely, because a
+  GhosttyKit miss is slow to rebuild.
+- The mirror clients have their own workflows, `.github/workflows/mirror-ios.yml` and
+  `.github/workflows/mirror-android.yml`. They run for changes to their client (and
+  `Mirror/Shared/` for iOS) and for each published release. They use the `release` event,
+  not a `v*` tag push: `scripts/release.sh` makes lightweight tags, which
+  `git push --follow-tags` does not push, and `gh release create` then makes the tag on
+  GitHub. The v2026.9.29 release recorded no tag push event. The release check runs after
+  publication, so it reports problems but does not block the Mac app release. CI runs only the iOS mirror unit tests (`make test-mirror-ios-unit`); the UI suite runs
+  locally with `make test-mirror-ios`. The Mac app workflow ignores changes to only the
+  mirror clients.
+- `make test-app` exports each pass's test action log (`*.action.json`), and the CI summary
+  shows when the test runner launch and the first test suite start.
+- `make lint` and `make check-localization` run in the parallel step beside the build, in the
+  `checks` task with the script tests, not as steps before it.
+
+## Test start time
+
+The test-progress heartbeat suggested that the first `xcodebuild test` pass waited 1.5–2
+minutes after the build before its first suite. The test action log shows that this is
+output buffering: xcodebuild writes test results to the pipe in bursts. In the measured run
+the build ended at 96 s, the test runner launched at 98.8 s and the first suite started at
+105.3 s; the tests then ran for about 85 s. Read test timing from the action-log summary, not
+from heartbeat timestamps.
+
+## Measurements (#851, hosted `macos-26` runner)
+
+Both runs missed the strict App incremental key because the pull request changes the
+Makefile and the workflows.
+
+| Run | Compile | "Build app and run tests" step | `build` job |
+| --- | ---: | ---: | ---: |
+| Before (no CAS) | about 10 min | 782 s | 16 min 28 s |
+| After (CAS from the newest main entry, 1.3 GB) | about 2 min 20 s | 322 s | 8 min 46 s |
+| After, second run (516 Swift cache hits, 30 misses) | 96 s build | 267 s | 7 min 33 s |
+
+Hosted runner speed varies about 2x between runs, so these are single samples, not medians.
+In the second run, restoring caches took 98 s (SwiftPM 34 s, App state 25 s, CLI 15 s), the
+main test pass about 90 s, and the three isolated `test-without-building` passes about 60 s.
+
+## Open questions
+
+- The SwiftPM cache (1.46 GB, mostly repository clones and the Sentry binary artifact) is the
+  slowest restore. Removing the clones may make SwiftPM fetch them again; not measured.
+
+## Refs
+
+PR #851.
diff --git a/docs-ai/README.md b/docs-ai/README.md
index 11aca6631..d76d41f11 100644
--- a/docs-ai/README.md
+++ b/docs-ai/README.md
@@ -98,7 +98,7 @@ keep the old paths. Use this table to find a file that an old entry names:
 | 013 | [prowl-cli](013-prowl-cli/000-plan.md) | 2026-03-30 | Contract-first `prowl` CLI: socket service, v1 commands, hardening, agents |
 | 014 | [terminal-layout-persistence](014-terminal-layout-persistence/000-plan.md) | 2026-03-31 | Layout snapshot save/restore; font-size persistence; launch races |
 | 015 | [repositories-feature-refactor](015-repositories-feature-refactor/000-plan.md) | 2026-04-03 | TCA decomposition of RepositoriesFeature and later code-health splits |
-| 016 | [dev-build-and-ci-workflow](016-dev-build-and-ci-workflow/000-plan.md) | 2026-04-04 | Build/test tooling, CI parallelism, Debug identity, incremental caching, Shared module boundary |
+| 016 | [dev-build-and-ci-workflow](016-dev-build-and-ci-workflow/000-plan.md) | 2026-04-04 | Build/test tooling, CI parallelism, Debug identity, incremental caching, Shared module boundary, CAS fallback and cache save scope |
 | 017 | [upstream-sync-process](017-upstream-sync-process/000-plan.md) | 2026-04-08 | Upstream review discipline, baselines, batch decisions |
 | 018 | [archived-worktrees](018-archived-worktrees/000-plan.md) | 2026-04-09 | Archived worktree discoverability and auto-delete |
 | 019 | [worktree-creation-and-lifecycle](019-worktree-creation-and-lifecycle/000-plan.md) | 2026-04-12 | Creation/merge flows, safe deletion, Add-to-Prowl redesign |
diff --git a/scripts/select_ios_simulator.py b/scripts/select_ios_simulator.py
index 530704698..69e5c3954 100644
--- a/scripts/select_ios_simulator.py
+++ b/scripts/select_ios_simulator.py
@@ -5,6 +5,9 @@
 expression for the full name (for example `iPhone [0-9]+ Pro`). The newest matching
 model on the newest runtime that the selected Xcode supports is used.
 """
+# macOS includes Python 3.9, which cannot evaluate `X | None` annotations at run time.
+from __future__ import annotations
+
 import json
 import re
 import subprocess
diff --git a/scripts/summarize-xcode-build.py b/scripts/summarize-xcode-build.py
index 6f9643cb9..2eb64e26b 100644
--- a/scripts/summarize-xcode-build.py
+++ b/scripts/summarize-xcode-build.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""Summarize xcresulttool build logs without adding overlapping task times."""
+"""Summarize xcresulttool build logs without adding overlapping task times, and test action logs."""
 
 import json
 from pathlib import Path
@@ -26,11 +26,45 @@ def summarize(log, name):
     return "\n".join(lines) + "\n"
 
 
+def sections(node):
+    for child in node.get("subsections", []):
+        yield child
+        yield from sections(child)
+
+
+def summarize_test_launch(log, name):
+    """Show when the test runner launch and the first test suite start in a test action log.
+
+    A large gap between them is time before any test runs (for example a slow first launch of
+    the test host), which the build log and the test results do not show.
+    """
+    start = log.get("startTime", 0)
+
+    def first(prefix):
+        times = [
+            section["startTime"] for section in sections(log)
+            if section.get("title", "").startswith(prefix) and "startTime" in section
+        ]
+        return min(times) - start if times else None
+
+    lines = [f"### {name}", "", f"Test action: **{log.get('duration', 0):.1f} s**", ""]
+    for label, offset in (
+        ("Test runner launch", first("Launching ")),
+        ("First test suite", first("Run test suite ")),
+    ):
+        lines.append(f"- {label}: not recorded" if offset is None else f"- {label} starts at **{offset:.1f} s**")
+    return "\n".join(lines) + "\n"
+
+
 if __name__ == "__main__":
     for argument in sys.argv[1:]:
         path = Path(argument)
         try:
-            print(summarize(json.loads(path.read_text()), path.name))
+            log = json.loads(path.read_text())
+            if path.name.endswith(".action.json"):
+                print(summarize_test_launch(log, path.name))
+            else:
+                print(summarize(log, path.name))
         except (OSError, ValueError, KeyError, TypeError) as error:
             # Build diagnostics must not replace the build or test exit status.
             print(f"Build metrics unavailable for {path.name}: {error}", file=sys.stderr)
diff --git a/scripts/test_developer_onboarding.py b/scripts/test_developer_onboarding.py
index 6cc4b2558..a0b442f6e 100644
--- a/scripts/test_developer_onboarding.py
+++ b/scripts/test_developer_onboarding.py
@@ -25,10 +25,10 @@ def test_mirror_readmes_describe_revision_matched_hosts(self):
                 self.assertIn(expected, readme)
                 self.assertNotIn("feat/mobile-mirror", readme)
 
-    def test_ios_readme_has_a_repeatable_cross_device_test_command(self):
+    def test_ios_readme_has_a_repeatable_test_command(self):
         readme = (ROOT / "Mirror/iOS/README.md").read_text()
         self.assertIn("make test-mirror-ios", readme)
-        self.assertIn("matching simulator form factors", readme)
+        self.assertIn("CI runs only the unit tests", readme)
 
     def test_android_readme_accepts_android_studios_bundled_jbr(self):
         readme = (ROOT / "Mirror/Android/README.md").read_text()
diff --git a/scripts/test_summarize_xcode_build.py b/scripts/test_summarize_xcode_build.py
index 11cc5abc3..014e807ff 100644
--- a/scripts/test_summarize_xcode_build.py
+++ b/scripts/test_summarize_xcode_build.py
@@ -38,6 +38,34 @@ def test_missing_metrics_remain_unknown(self):
         self.assertIn("Cache counters unavailable", result)
         self.assertNotIn("0%", result)
 
+    def test_reports_when_the_test_runner_and_the_first_suite_start(self):
+        log = {
+            "startTime": 100,
+            "duration": 200,
+            "subsections": [
+                {"title": "Launch actions", "startTime": 100, "subsections": [
+                    {"title": "Launch AppTests", "startTime": 140, "subsections": [
+                        {"title": "Launching AppTests", "startTime": 140},
+                    ]},
+                ]},
+                {"title": "Test target AppTests", "startTime": 140, "subsections": [
+                    {"title": "App (42)", "startTime": 140, "subsections": [
+                        {"title": "Run test suite B", "startTime": 231},
+                        {"title": "Run test suite A", "startTime": 230},
+                    ]},
+                ]},
+            ],
+        }
+        result = module.summarize_test_launch(log, "test.action.json")
+        self.assertIn("Test action: **200.0 s**", result)
+        self.assertIn("Test runner launch starts at **40.0 s**", result)
+        self.assertIn("First test suite starts at **130.0 s**", result)
+
+    def test_missing_launch_sections_remain_unknown(self):
+        result = module.summarize_test_launch({"startTime": 0, "duration": 5}, "test.action.json")
+        self.assertIn("Test runner launch: not recorded", result)
+        self.assertIn("First test suite: not recorded", result)
+
 
 if __name__ == "__main__":
     unittest.main()