chore: prepare project for open source release

- Remove internal planning docs (CLAUDE.md, docs/, feature.md, livePlan.md) from git tracking
- Add .gitignore rules to prevent re-tracking internal files
- Add README.md (Chinese) and README.en.md (English) with screenshots, features, quick start
- Add LICENSE (MIT)
- Add CONTRIBUTING.md with dev setup, commit conventions, PR guide
- Add CHANGELOG.md for v1.0.0
- Add .github/ issue templates (bug report, feature request) and PR template
- Add public/ screenshots (p1-p6)

.gitignore

@@ -42,3 +42,9 @@ yarn-error.*
 
 # git worktrees
 .worktrees/
+
+# Internal AI instructions & planning docs
+CLAUDE.md
+docs/
+feature.md
+livePlan.md