docs(github): add commit helper agent and references

- Add commit.agent.md with branch validation workflow
- Include commit instructions for AI coding assistants
- Add Conventional Commits specification reference
- Implement Step 0 branch checking before commits

Reviewed-by: Claude Sonnet 4.5

1 files changed, 38 insertions, 0 deletions

diff --git a/.github/instructions/commit.instructions.md b/.github/instructions/commit.instructions.md
new file mode 100644
index 0000000..cc29e9c
--- /dev/null
+++ b/.github/instructions/commit.instructions.md
@@ -0,0 +1,38 @@
+---
+applyTo: "**"
+---
+
+# Commit Helper Instructions
+
+When user requests commit help → Follow <a>.github/agents/commit.agent.md</a>
+
+## Critical Rules
+
+1. **Language**: Commit message ALWAYS in **English** (unless user specifies otherwise)
+2. **Explanation**: Use **user's request language** ONLY when commit language differs
+   - Chinese user + English commit → Explain in Chinese
+   - English user + Chinese commit → Explain in English
+   - Same language → No extra explanation needed
+3. **Confirmation**: ALWAYS ask before committing (unless "commit directly" requested)
+
+## Quick Reference
+
+**Format**: `<type>[scope]: <description>`
+
+**Common types**: `feat` `fix` `docs` `refactor` `perf` `test` `chore`
+
+**AI commits MUST include**: `Reviewed-by: [MODEL_NAME]`
+
+**Spec**: <a>.github/references/git/conventional-commit.md</a>
+
+## Common Mistakes
+
+| Wrong | Right |
+|-------|-------|
+| `feat: Added feature` | `feat: add feature` (imperative) |
+| `Fix bug.` | `fix: resolve auth issue` (lowercase, no period) |
+| `feat: add A, refactor B, update C` | Split into 3 commits |
+
+## User Triggers
+
+"create commit", "commit message", "conventional commit"
\ No newline at end of file