Build the initial PatchSlim CLI

.codex/skills/use-patchslim/SKILL.md

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+---
+name: use-patchslim
+description: Inspect and minimize committed Git branch diffs with the PatchSlim CLI while preserving protected tests and configured checks. Use when a user asks to shrink a large pull request, remove unnecessary branch changes, test whether diff hunks are required, or review a PatchSlim report.
+---
+
+# Use PatchSlim
+
+Verify the installation and repository before minimizing:
+
+```bash
+command -v patchslim
+patchslim --json doctor
+patchslim --json inspect --base main
+```
+
+Do not start minimization until the user has identified a feature-specific
+oracle. Prefer a targeted check that fails at the base revision and passes at
+the branch head.
+
+Run the reducer with layered checks:
+
+```bash
+patchslim --json minimize \
+  --base main \
+  --oracle "pnpm vitest run path/to/regression.test.ts" \
+  --quick "pnpm typecheck" \
+  --gate "pnpm test"
+```
+
+After completion:
+
+1. Read the generated JSON report.
+2. Inspect the candidate patch.
+3. Run `git apply --check <apply.patch>` against the original head.
+4. Explain that the result is oracle-backed evidence, not proof of equivalence.
+
+Follow these rules:
+
+- Prefer `--json` for stable output.
+- Keep tests, fixtures, migrations, lockfiles, and CI configuration protected
+  unless the user explicitly changes that boundary.
+- Do not apply, commit, push, or open a pull request unless the user asks.
+- Do not run PatchSlim against untrusted repository content.
+- Stop when the oracle is weak, unstable, or produces an unexpected baseline
+  result.

.codex/skills/use-patchslim/agents/openai.yaml

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+interface:
+  display_name: "Use PatchSlim"
+  short_description: "Minimize Git diffs with test-guided checks"
+  default_prompt: "Use $use-patchslim to inspect and safely minimize this branch diff."

.github/workflows/ci.yml

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+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    name: Node ${{ matrix.node-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version:
+          - 20
+          - 22
+          - 24
+    steps:
+      - uses: actions/checkout@v7.0.1
+      - uses: pnpm/action-setup@v6.0.9
+        with:
+          version: 10.34.5
+      - uses: actions/setup-node@v7.0.0
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: pnpm
+      - run: pnpm install --frozen-lockfile
+      - run: pnpm check

.markdownlint.json

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+{
+  "MD013": false
+}

.prettierignore

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+dist
+node_modules
+pnpm-lock.yaml
+.patchslim

CHANGELOG.md

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+# Changelog
+
+All notable changes to PatchSlim are documented here.
+
+## 0.1.0 — 2026-07-29
+
+Initial preview release.
+
+### Added
+
+- File-level and hunk-level delta debugging for committed Git branch diffs.
+- `doctor`, `init`, `inspect`, `minimize`, and `report` commands with stable
+  JSON output.
+- Merge-base discovery, isolated temporary worktrees, candidate caching, and
+  bounded command execution.
+- Conservative protection for tests, fixtures, snapshots, migrations,
+  documentation, CI, manifests, lockfiles, PatchSlim configuration, and Git
+  control files.
+- Head-pass/protected-base-fail preflight with repeated instability checks.
+- Quick candidate gates, repeated final oracles, and full validation gates.
+- `apply.patch`, `candidate.patch`, JSON reports, and Markdown reports.
+
+### Safety
+
+- Rejects weak or unstable oracles, red head gates, dirty setup output,
+  candidate materialization failures, timeouts, and interruptions.
+- Reconstructs every command stage from the merge base and clears ignored
+  side effects between stages.
+- Never applies a candidate to the current checkout automatically.
+
+### Verified
+
+- JavaScript and Python fixtures.
+- Text hunks, added files, binary diffs, renames, mode changes, paths with
+  spaces, and Unicode paths.
+- Exact application of `apply.patch` to the original head.
+- Node.js 20, 22, and 24, package linting, clean production dependency audit,
+  and GitHub Actions.

CONTRIBUTING.md

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+# Contributing
+
+Thanks for taking the time to improve PatchSlim.
+
+## Development setup
+
+PatchSlim requires Node.js 20 or newer and pnpm.
+
+```bash
+pnpm install
+pnpm check
+```
+
+Keep pull requests focused. Include tests for behavior changes and explain any
+change to candidate construction, protection rules, or command execution.
+
+## Safety invariants
+
+Changes to the reducer must preserve these guarantees:
+
+- the user's current checkout is never reset or cleaned;
+- candidate evaluation happens in a temporary worktree;
+- protected changes remain in every candidate;
+- minimization stops when the full branch fails or the protected-only baseline
+  passes;
+- a candidate is never applied automatically;
+- command output remains bounded and machine-readable output remains stable.
+
+Use temporary repositories in tests for Git behavior. Tests must not rely on a
+developer's global Git configuration or modify repositories outside their own
+temporary directory.
+
+## Commit and pull request style
+
+Write short, imperative commit subjects. In the pull request, describe the
+observable behavior, the checks you ran, and any known limitation.