docs: add git commit conventions

Author: codeboyzhou

AGENTS.md

@@ -0,0 +1,41 @@
+# Git Commit Rules
+
+When committing code, you MUST follow these rules:
+
+## Commit message format
+
+Use Conventional Commits:
+
+`<type>(<scope>): <subject>`
+
+Allowed types:
+
+- feat
+- fix
+- docs
+- style
+- refactor
+- perf
+- test
+- build
+- ci
+- chore
+
+Examples:
+
+feat(auth): add oauth login support
+
+fix(order): prevent duplicate payment processing
+
+Rules:
+
+- subject must be lowercase
+- subject max length 72 chars
+- no period at the end
+- use imperative mood
+- commit message must be written in English
+
+Before committing:
+
+- run git diff --cached
+- verify commit message format