[AI] Establish AI agent commit and PR guidelines (#7153)

* [AI] Extract PR/commit rules into shared agent skill

Deduplicate PR and commit instructions from AGENTS.md into a standalone
skill file at .github/agents/pr-and-commit-rules.md. This single source
of truth is consumed by both Claude Code (via CLAUDE.md @-import) and
Cursor (via .cursor/rules/pr-and-commit.mdc with alwaysApply: true).

AGENTS.md now references the shared file instead of repeating the rules
in three separate sections.

https://claude.ai/code/session_01KkHg7MYXrTyDkTw6u98Vam

* Add release notes for PR #7153

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

.cursor/rules/pr-and-commit.mdc

@@ -0,0 +1,74 @@
+---
+description: Rules for AI-generated commits and pull requests
+globs:
+alwaysApply: true
+---
+
+# PR and Commit Rules for AI Agents
+
+Canonical source: `.github/agents/pr-and-commit-rules.md`
+
+## Commit Rules
+
+### [AI] Prefix Requirement
+
+**ALL commit messages MUST be prefixed with `[AI]`.** This is a mandatory requirement with no exceptions.
+
+**Examples:**
+
+- `[AI] Fix type error in account validation`
+- `[AI] Add support for new transaction categories`
+- `Fix type error in account validation` (MISSING PREFIX - NOT ALLOWED)
+- `Add support for new transaction categories` (MISSING PREFIX - NOT ALLOWED)
+
+### Git Safety Rules
+
+- **Never** update git config
+- **Never** run destructive git operations (force push, hard reset) unless the user explicitly requests it
+- **Never** skip hooks (`--no-verify`, `--no-gpg-sign`)
+- **Never** force push to `main`/`master`
+- **Never** commit unless explicitly asked by the user
+
+## Pre-Commit Quality Checklist
+
+Before committing, ensure all of the following:
+
+- [ ] Commit message is prefixed with `[AI]`
+- [ ] `yarn typecheck` passes
+- [ ] `yarn lint:fix` has been run
+- [ ] Relevant tests pass
+- [ ] User-facing strings are translated
+- [ ] Code style conventions followed (see `AGENTS.md` for full style guide)
+
+## Pull Request Rules
+
+### [AI] Prefix Requirement
+
+**ALL pull request titles MUST be prefixed with `[AI]`.** This is a mandatory requirement with no exceptions.
+
+**Examples:**
+
+- `[AI] Fix type error in account validation`
+- `[AI] Add support for new transaction categories`
+- `Fix type error in account validation` (MISSING PREFIX - NOT ALLOWED)
+
+### Labels
+
+Add the **"AI generated"** label to all AI-created pull requests.
+
+### PR Template: Do Not Fill In
+
+- **NEVER fill in the PR template** (`.github/PULL_REQUEST_TEMPLATE.md`). Leave all blank spaces and placeholder comments as-is.
+- **Exception**: If a human **explicitly asks** you to fill out the PR template, then fill it out **in Chinese** (简体中文).
+
+## Quick-Reference Workflow
+
+1. Make your changes
+2. Run `yarn typecheck` — fix any errors
+3. Run `yarn lint:fix` — fix any remaining lint errors
+4. Run relevant tests (`yarn test` for all, or workspace-specific)
+5. Stage files and commit with `[AI]` prefix — do not skip hooks
+6. When creating a PR:
+   - Use `[AI]` prefix in the title
+   - Add the `"AI generated"` label
+   - Leave the PR template blank (do not fill it in)