feat: selective git auto-tag at idd-issue baseline + idd-verify PASS (#85)

idd-issue tags idd-{N}-baseline at main HEAD (rollback anchor); idd-verify
tags idd-{N}-verified at the Aggregate-PASS snapshot (review-ready). Only
these two milestones (no diagnose/plan/implement tags) so the tag namespace
stays clean. Config auto_tag (default-on, opt-out via enabled:false);
idempotent (existing tag skipped) + graceful-skip on push failure (never
aborts the workflow). New auto-tag drift-guard, 27 assertions.

Refs #85

Author: kiki830621

plugins/issue-driven-dev/README.md

@@ -206,6 +206,18 @@ attachments_release: "attachments"
 ---
 ```
 
+### Selective auto-tag（v2.94.0, #85）
+
+IDD tags two milestones so you can jump back to a stable checkpoint with `git checkout` instead of hunting commit hashes: `idd-{N}-baseline` (placed by `idd-issue` on main's HEAD when the issue opens — the rollback anchor) and `idd-{N}-verified` (placed by `idd-verify` on the Aggregate-PASS snapshot — review-ready). Only these two points are tagged (no `diagnose`/`plan`/`implement` tags), so the tag namespace stays clean.
+
+**Default-ON**, opt-out via config. Tagging includes a `git push` (a repo-wide side effect), is idempotent (existing tag → skip), and graceful-skips on any push failure (never aborts the workflow). Turn it off with:
+
+```json
+{ "auto_tag": { "enabled": false } }
+```
+
+Full schema (`enabled` / `baseline_format` / `verified_format` / `push_remote`) in [references/config-protocol.md](references/config-protocol.md) → `auto_tag` field.
+
 ## Deep Integrations（深度整合套件總覽）
 
 IDD 遵循「**深度整合 >> hard-coded**」原則（#209/#214）：生態系已有 canonical 套件時依賴它、不在內部複製等價邏輯。每個整合的綁定形狀與缺席行為：

plugins/issue-driven-dev/references/config-protocol.md

@@ -480,6 +480,30 @@ An OPTIONAL identity registry so IDD can resolve a person's alias / email / disp
 
 **PII boundary (important).** `email` is personally-identifiable and MUST NOT live in a committed / public config. Keep the non-PII fields (`github_login` / `display_name` / `role` / `aliases`) in the normal walked-up config; put `email` only in a **private / gitignored** config layer. `idd-config validate` emits a PII reminder whenever it sees an `email` in a registry entry, so a leak into a tracked config is surfaced early. This mirrors the git-privacy boundary: a person's raw email is third-party PII, not your own derivative content.
 
+### `auto_tag` field
+
+An OPTIONAL object that turns on **selective git-tag automation** at two high-value IDD milestones (#85): `idd-issue` tags the rollback baseline, `idd-verify` tags the review-ready snapshot. Deliberately *selective* — only these two points get a tag, so a long-running repo doesn't accumulate hundreds of stale lifecycle tags.
+
+```json
+{
+  "auto_tag": {
+    "enabled": true,
+    "baseline_format": "idd-{N}-baseline",
+    "verified_format": "idd-{N}-verified",
+    "push_remote": "origin"
+  }
+}
+```
+
+| Field | Default | Meaning |
+|-------|---------|---------|
+| `enabled` | `true` | Master switch. **Default-ON**: with no config, `idd-issue` / `idd-verify` create + push these tags automatically. Set `enabled: false` to opt out completely. |
+| `baseline_format` | `idd-{N}-baseline` | Tag placed by `idd-issue` on the local default-branch HEAD at issue-open time (the rollback anchor). `{N}` = issue number. |
+| `verified_format` | `idd-{N}-verified` | Tag placed by `idd-verify` on the Aggregate-PASS snapshot (PR head in PR mode, current HEAD in local mode). |
+| `push_remote` | `origin` | Remote the tags are pushed to. |
+
+**Side-effect note (important).** Tag creation includes a `git push` to `push_remote` — a **repo-wide side effect** visible to everyone with the remote. Because the default is **ON**, a fresh IDD user gets `idd-{N}-baseline` / `idd-{N}-verified` tags on their remote without asking; `enabled: false` is the one-line opt-out. Tagging is **idempotent** (a tag that already exists is skipped, so re-runs never re-tag) and **graceful-skip** (a push failure on a fork / permission-denied / rejected remote warns and continues — it never aborts the `idd-issue` / `idd-verify` workflow). Intermediate lifecycle steps (`diagnose` / `plan` / `implement`) are deliberately **not** tagged; phase-level tagging stays manual.
+
 ## Resolution algorithm (canonical)
 
 ```

plugins/issue-driven-dev/scripts/tests/auto-tag/test.sh

@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+# test.sh — drift-guard for selective git auto-tag (#85).
+#
+# #85 adds selective git-tag automation at two IDD milestones:
+#   - idd-issue creates `idd-{N}-baseline` (main HEAD at issue-open = rollback anchor)
+#   - idd-verify creates `idd-{N}-verified` on Aggregate PASS (review snapshot)
+# opt-out via config `auto_tag.enabled`, idempotent, graceful-skip on push failure.
+#
+# WHY A CONTENT DRIFT-GUARD: the tag behaviors live in prose SKILL.md files
+# (idd-issue Step 0/creation, idd-verify Aggregate-PASS branch) + a config schema
+# (config-protocol.md) — AI prompts, not executable code. The falsifiable
+# equivalent is asserting each file encodes the tag contract. The schema is
+# documented across files that MUST agree; the failure mode is DRIFT (rename a
+# format key in the schema, forget the SKILL that references it). Needles below
+# are distinctive to #85 (0-occurrence before the change), so each is a genuine
+# drift signal.
+#
+# Usage: bash test.sh   (exit 0 = all pass, 1 = any fail)
+
+set -u
+
+HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PLUGIN_ROOT="$HERE/../../.."
+PROTOCOL="$PLUGIN_ROOT/references/config-protocol.md"
+ISSUE="$PLUGIN_ROOT/skills/idd-issue/SKILL.md"
+VERIFY="$PLUGIN_ROOT/skills/idd-verify/SKILL.md"
+README="$PLUGIN_ROOT/README.md"
+
+HELPERS="$HERE/../../lib/assert-helpers.sh"
+[ -f "$HELPERS" ] || { echo "✗ missing $HELPERS — cannot run suite" >&2; exit 1; }
+. "$HELPERS"
+
+assert_file_exists "config-protocol.md exists" "$PROTOCOL"
+assert_file_exists "idd-issue SKILL.md exists" "$ISSUE"
+assert_file_exists "idd-verify SKILL.md exists" "$VERIFY"
+assert_file_exists "plugin README.md exists" "$README"
+
+# ── config-protocol.md: the auto_tag schema (source of truth) ──
+assert_output_grep "protocol: declares the auto_tag field section" "### \`auto_tag\` field" "$PROTOCOL"
+assert_output_grep "protocol: auto_tag config key"                 "auto_tag"               "$PROTOCOL"
+assert_output_grep "protocol: enabled key (default-on / opt-out)"  "enabled"                "$PROTOCOL"
+assert_output_grep "protocol: baseline_format key"                 "baseline_format"        "$PROTOCOL"
+assert_output_grep "protocol: verified_format key"                 "verified_format"        "$PROTOCOL"
+assert_output_grep "protocol: push_remote key"                     "push_remote"            "$PROTOCOL"
+assert_output_grep "protocol: baseline tag naming default"         "idd-{N}-baseline"       "$PROTOCOL"
+assert_output_grep "protocol: verified tag naming default"         "idd-{N}-verified"       "$PROTOCOL"
+# default-ON must be explicit + opt-out documented (user decision 2026-07-09)
+assert_output_grep "protocol: default-on documented"               "default"                "$PROTOCOL"
+assert_output_grep "protocol: opt-out documented"                  "enabled: false"         "$PROTOCOL"
+# tag push is a repo-wide side effect — must be surfaced so default-on isn't a surprise
+assert_output_grep "protocol: push side-effect surfaced"           "side effect"            "$PROTOCOL"
+
+# ── idd-issue: baseline tag after issue creation ──
+assert_output_grep "idd-issue: tag_baseline bootstrap step"        "tag_baseline"           "$ISSUE"
+assert_output_grep "idd-issue: baseline tag naming"                "idd-{N}-baseline"       "$ISSUE"
+assert_output_grep "idd-issue: gated on auto_tag config"           "auto_tag"               "$ISSUE"
+assert_output_grep "idd-issue: idempotent (tag exists → skip)"     "idempotent"             "$ISSUE"
+assert_output_grep "idd-issue: graceful-skip on push failure"      "graceful-skip"          "$ISSUE"
+# never abort the workflow on tag failure (warn-continue discipline)
+assert_output_grep "idd-issue: tag failure never aborts"           "never abort"            "$ISSUE"
+
+# ── idd-verify: verified tag on Aggregate PASS ──
+assert_output_grep "idd-verify: tag_verified bootstrap step"       "tag_verified"           "$VERIFY"
+assert_output_grep "idd-verify: verified tag naming"               "idd-{N}-verified"       "$VERIFY"
+assert_output_grep "idd-verify: gated on auto_tag config"          "auto_tag"               "$VERIFY"
+assert_output_grep "idd-verify: fires on Aggregate PASS"           "Aggregate PASS"         "$VERIFY"
+
+# ── README: discoverability note ──
+assert_output_grep "README: auto-tag convention documented"        "auto_tag"               "$README"
+assert_output_grep "README: baseline/verified naming shown"        "idd-{N}-baseline"       "$README"
+
+print_summary "auto-tag (#85)"

plugins/issue-driven-dev/skills/idd-issue/SKILL.md

@@ -112,6 +112,7 @@ TaskCreate(name="attach_images", description="上傳圖片到 attachments releas
 TaskCreate(name="create_milestone", description="來源為文件時自動建立 milestone 並指派(見 Step 4.5)")
 TaskCreate(name="clarity_surface", description="Step 4.6: delegate to /idd-clarify $NEW_ISSUE_NUMBER per IC clarity axis (skip in --multi-finding mode); failure → emit 'deferred' placeholder block + continue to Step 4.7 (per #135 v4 composable primitive design)")
 TaskCreate(name="linked_context_sister_sweep", description="Step 4.7: scan body draft + linked attachments + recent session conversation for sibling-concern markers (also / additionally / 另外 / 順便 / etc); if hits AskUserQuestion 3-option per canonical references/ic-r011-checkpoint.md; PATCH just-created issue body with `### Linked-Context Siblings Filed` audit trail (advisory, non-blocking, per IC_R011 #529)")
+TaskCreate(name="tag_baseline", description="Step 3.6 (#85): if config auto_tag.enabled (default on), tag idd-{N}-baseline at the local default-branch HEAD (rollback anchor) + git push push_remote. Idempotent (tag exists → skip + note); graceful-skip on push failure (never abort). Skip when auto_tag.enabled=false.")
 TaskCreate(name="report_and_stop", description="回報 issue number/URL(group 模式列全部 + cross-link),停下等使用者決定下一步")
 ```
 
@@ -963,6 +964,38 @@ AskUserQuestion:
 
 - [~] **Native relationship suggestion (deferred)** — body 內 `#N` 用 GitHub 2024+ GraphQL（`addBlockedByDependency` 等）建 structured relationship，比 body text reference 多 sidebar backlink。**本 cluster 刻意不做**，理由：(1) 複雜度/風險最高（需 relationship-type picker UI）；(2) #141 spec 自身將其框為「reuse v2.52.0+ `--blocked-by` code path」的後續工作，而該 path 尚未一般化成可獨立呼叫的 primitive；(3) design Q4 裁定 body text reference 本來就保留（與 native backlink 互補不重複），所以延後不損失現有 inline context。點亮條件：`--blocked-by` 的 GraphQL mutation 抽成可重用 helper 後，再接本 (d)。
 
+### Step 3.6: Baseline auto-tag（rollback anchor，v2.94.0+，#85）
+
+Issue 建立成功、拿到 `$NUMBER` 之後，`tag_baseline` step 在當前 repo 打一個 **rollback baseline** tag，標記「issue 開案當下的 main HEAD」，方便日後一秒切回開工前的乾淨狀態（`git checkout idd-{N}-baseline`），不用記 commit hash。
+
+**Config gate（預設 on，可 opt-out）** — 讀 walked-up config 的 `auto_tag`（schema 見 [`references/config-protocol.md`](../../references/config-protocol.md#auto_tag-field)）：
+
+```bash
+AUTO_TAG_ENABLED=$(jq -r '.auto_tag.enabled // true' "$CONFIG_PATH" 2>/dev/null || echo true)
+[ "$AUTO_TAG_ENABLED" = "false" ] && { echo "→ auto_tag disabled — skipping baseline tag"; }   # opt-out: skip entirely
+```
+
+啟用時：
+
+```bash
+BASELINE_FMT=$(jq -r '.auto_tag.baseline_format // "idd-{N}-baseline"' "$CONFIG_PATH" 2>/dev/null || echo "idd-{N}-baseline")
+PUSH_REMOTE=$(jq -r '.auto_tag.push_remote // "origin"' "$CONFIG_PATH" 2>/dev/null || echo origin)
+TAG="${BASELINE_FMT/\{N\}/$NUMBER}"                       # idd-{N}-baseline → idd-42-baseline
+DEFAULT_BRANCH=$(gh repo view "$GITHUB_REPO" --json defaultBranchRef -q .defaultBranchRef.name)
+
+# idempotent: a tag that already exists is skipped (re-running idd-issue never re-tags)
+if git rev-parse -q --verify "refs/tags/$TAG" >/dev/null; then
+    echo "→ $TAG already exists — skip (idempotent)"
+else
+    # baseline = the LOCAL default-branch HEAD (where main was when the issue opened)
+    git tag "$TAG" "$DEFAULT_BRANCH" && git push "$PUSH_REMOTE" "$TAG" \
+        && echo "→ tagged $TAG at $DEFAULT_BRANCH HEAD + pushed to $PUSH_REMOTE" \
+        || echo "⚠ auto_tag baseline: git tag/push failed (fork / no push permission / rejected) — graceful-skip, continuing"
+fi
+```
+
+**鐵律 — graceful-skip，never abort**：tag 或 push 失敗（fork 無 push 權限、remote reject、default-branch 解析失敗等）**只 warn，絕不 abort** `idd-issue`（per IDD warn-continue pattern）。tag 是便利 checkpoint，不是 issue 建立的成敗條件。fork-aware：tag 打在當前 cwd 的 repo（Step 0.5 解析結果），push 到 `push_remote`（預設 `origin`）。intermediate step（diagnose / plan / implement）不 tag；phase-level tag 留手動。
+
 ### Step 4: 附加所有原始素材（鐵律：預設全保留）
 
 > 引用 Step 1 的「資料保留鐵律」：來源中**任何附件都要全部上傳**，不論張數、不論格式。

plugins/issue-driven-dev/skills/idd-verify/SKILL.md

@@ -265,6 +265,7 @@ TaskCreate(name="recovery_protocol", description="Step 2.5 (NEW per #52): 缺 fi
 TaskCreate(name="wait_for_codex", description="等 Codex 背景任務完成,讀 /tmp/codex-verify-${NUMBER}.md")
 TaskCreate(name="merge_findings", description="合併 6 個來源 findings 去重,severity 取最高")
 TaskCreate(name="post_master_and_pointers", description="PR mode: master 貼到 PR + capture URL → 為每個 ref'd issue 貼 pointer comment；本地 mode: 貼到 issue（單 issue 直接貼／多 issue 用 SOP master+pointer）")
+TaskCreate(name="tag_verified", description="Step 4.5 (#85): if config auto_tag.enabled (default on) AND Aggregate PASS, tag idd-{N}-verified at the PR head (PR mode) / current HEAD (local mode) + git push. Idempotent + graceful-skip. Cluster: tag each ref'd #N. Skip on FAIL or auto_tag.enabled=false.")
 TaskCreate(name="restore_working_tree", description="PR mode 結束後 git checkout 回原 branch（Step 0.5 記住的）")
 TaskCreate(name="decide_next_action", description="根據 findings: 通過→idd-close / 有 findings→修正 / scope creep→新 issue")
 TaskCreate(name="triage_followup_issues", description="Step 5b: 分類 non-blocking findings → 問使用者要不要開新 issue，確認後批次建立")
@@ -911,6 +912,37 @@ Verified scope: #98, #105
 | 2 | P3 | ... | agents:security | Follow-up |
 ```
 
+### Step 4.5: Verified auto-tag（review snapshot，v2.94.0+，#85）
+
+Master report 貼出、且 **Aggregate PASS** 後，`tag_verified` step 在 review-ready 的 snapshot 打 `idd-{N}-verified` tag —— 一個 stable handle，日後可直接 `git checkout idd-{N}-verified` 切回「verify 通過那一刻」的 code，或在 PR / issue comment 引用給 reviewer。**只在 PASS 打**（FAIL 不 tag —— snapshot 的價值是「這是驗過的版本」）。
+
+**Config gate（同 idd-issue baseline，預設 on）** — 讀 `auto_tag`（schema 見 [`references/config-protocol.md`](../../references/config-protocol.md#auto_tag-field)）：
+
+```bash
+# Only when Aggregate verdict == PASS
+[ "$AGGREGATE_VERDICT" != "PASS" ] && { echo "→ verify FAIL — no verified tag"; }   # FAIL: no snapshot tag
+AUTO_TAG_ENABLED=$(jq -r '.auto_tag.enabled // true' "$CONFIG_PATH" 2>/dev/null || echo true)
+[ "$AUTO_TAG_ENABLED" = "false" ] && { echo "→ auto_tag disabled — skipping verified tag"; }   # opt-out
+
+VERIFIED_FMT=$(jq -r '.auto_tag.verified_format // "idd-{N}-verified"' "$CONFIG_PATH" 2>/dev/null || echo "idd-{N}-verified")
+PUSH_REMOTE=$(jq -r '.auto_tag.push_remote // "origin"' "$CONFIG_PATH" 2>/dev/null || echo origin)
+# snapshot target: PR head (PR mode) / current HEAD (local mode)
+SNAPSHOT=$([ "$INPUT_SOURCE" = "pr" ] && echo "$PR_HEAD_SHA" || echo HEAD)
+
+for N in $ISSUE_NUMBERS; do                                # cluster: tag each ref'd #N
+    TAG="${VERIFIED_FMT/\{N\}/$N}"                          # idd-{N}-verified → idd-42-verified
+    if git rev-parse -q --verify "refs/tags/$TAG" >/dev/null; then
+        echo "→ $TAG already exists — skip (idempotent)"    # re-verify never re-tags
+    else
+        git tag "$TAG" "$SNAPSHOT" && git push "$PUSH_REMOTE" "$TAG" \
+            && echo "→ tagged $TAG at verified snapshot + pushed" \
+            || echo "⚠ auto_tag verified: git tag/push failed — graceful-skip, continuing"
+    fi
+done
+```
+
+**鐵律 — graceful-skip，never abort**：同 baseline —— tag/push 失敗只 warn，絕不 abort verify（結果已 post，tag 是附加便利）。**Aggregate PASS 是唯一觸發條件**；FAIL run 不留 verified tag，避免把未過的 code 標成「已驗證」。cluster mode（多 `#N`）每個 issue 各打自己的 `idd-{N}-verified`。
+
 ### Step 5: 後續動作
 
 #### Step 5a: 分類 findings