ci: add dart format auto-fix and link-check workflows

.github/workflows/dart-format-fix.yml

@@ -0,0 +1,53 @@
+name: Dart Format Auto-Fix
+
+# Automatically run `dart format` on PRs and push fixes back when the code is
+# not properly formatted. This keeps style consistent without reviewer nudging.
+#
+# 对 PR 自动执行 `dart format`；格式不合规时由 bot 自动提交修复，
+# 避免 reviewer 反复挑格式问题。
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+  # Allow manual runs from the Actions tab (formats the default branch).
+  # 允许在 Actions 页手动触发（对默认分支执行格式化）。
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+jobs:
+  format:
+    name: Auto-format Dart code
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout PR head
+        uses: actions/checkout@v7
+        with:
+          # Use the PR's head ref so we can push fixes back to the same branch.
+          # 使用 PR 的 head ref，以便把修复推回同一分支。
+          ref: ${{ github.head_ref }}
+
+      - name: Setup Flutter
+        uses: subosito/flutter-action@v2
+        with:
+          channel: 'stable'
+          cache: true
+
+      - name: Format code
+        run: dart format .
+
+      - name: Commit and push fixes
+        # Only commit if dart format actually changed something.
+        # 仅当 dart format 确实产生了改动时才提交。
+        run: |
+          if [[ -n "$(git status --porcelain)" ]]; then
+            git config user.name "github-actions[bot]"
+            git config user.email "github-actions[bot]@users.noreply.github.com"
+            git commit -am "style: auto-format with dart format"
+            git push
+          else
+            echo "No formatting changes needed."
+          fi

.github/workflows/link-check.yml

@@ -0,0 +1,50 @@
+name: Link Check
+
+# Scan documentation for dead/broken links using lychee.
+# Only user-facing docs are checked to keep the job fast and avoid false
+# positives from internal/anchor links.
+#
+# 使用 lychee 扫描文档中的死链/坏链。仅检查用户向文档以提升速度、减少误报。
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    paths:
+      - 'README.md'
+      - 'README_zh.md'
+      - 'CHANGELOG.md'
+      - 'docs/**'
+  # Allow manual runs from the Actions tab.
+  # 允许在 Actions 页手动触发。
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  link-check:
+    name: Check documentation links
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      - name: Run lychee link checker
+        uses: lycheeverse/lychee-action@v2
+        with:
+          # Only scan the documented files; accept 200/206/301/302/304, timeouts
+          # and 429 (rate limit) are retried. Fail only on real broken links.
+          # 仅扫描文档文件；失败仅针对真正坏掉的链接。
+          args: >
+            --no-progress
+            --accept 200,206,301,302,304
+            --timeout 20
+            --retry-wait-time 2
+            --max-retries 2
+            --exclude-mail
+            README.md README_zh.md CHANGELOG.md "docs/**"
+          fail: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

AGENTS.md

@@ -46,6 +46,8 @@ This file defines the architecture, coding conventions, and required workflows f
 - `ci.yml`: `actions/checkout@v7`, `subosito/flutter-action@v2`, `actions/cache@v5` (pub cache keyed on `pubspec.lock` plus `example/pubspec.lock`); runs `flutter analyze`, `flutter test`, and `pana` score check.
 - `stale.yml`: `actions/stale@v11` marks stale issues/PRs.
 - `dependabot-pr-bilingual.yml`: `actions/github-script@v7` appends a bilingual (EN-primary, ZH-secondary) summary to the **body** of Dependabot PRs only (`github.actor == 'dependabot[bot]'`, idempotent via marker). It does NOT touch the PR title or commit subject — those stay English per the Conventional Commits rule. When reviewing Dependabot PRs, verify the build passes, check changelogs for breaking changes on major bumps, and confirm the caret (`^`) constraint is preserved.
+- `dart-format-fix.yml`: on PR `opened`/`synchronize`/`reopened` (and `workflow_dispatch` manual trigger), runs `dart format .` and, if it changed anything, auto-commits and pushes the fix back to the **same PR branch** as `github-actions[bot]`. Keeps style consistent without reviewer nudging. Note: uses `pull_request` (not `pull_request_target`) with `permissions: contents: write`; if branch protection blocks workflow pushes or requires signed commits, switch it to open a fix branch / post a comment instead.
+- `link-check.yml`: on PR changes to `README.md`, `README_zh.md`, `CHANGELOG.md`, `docs/**` (and `workflow_dispatch` manual trigger), runs `lychee-action@v2` to scan those docs for dead/broken links and fails only on real broken links (mailto and common redirects/rate-limits are excluded). Use the Actions tab manual run to scan the default branch on demand.
 - `pr-title-check.yml` details: allowed types are `feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert`; `requireScope` is `false`; PRs labeled `dependencies` or `github-actions` are ignored. The same type list applies to commit messages (Conventional Commits).
 - `paths-ignore` skips user-facing docs (`README*.md`, `CHANGELOG.md`, `TODO.md`, `wiki/**`, `docs/**`) to save CI minutes, but it MUST NOT blanket-ignore all `**.md`. `AGENTS.md` and `.codebuddy/**` are intentionally kept out of `paths-ignore` so docs-only PRs still run the required checks and can merge (branch protection requires 3 passing checks; a skipped `ci.yml` would block the merge). Never reintroduce `'**.md'` to `paths-ignore`.