feat(p1): complete P1 foundation stage

- monorepo: pnpm workspace + go.work + pyproject.toml + commitlint/husky
- infra: docker-compose (minimal + full profiles) + init-sql + prometheus
- arch-scan: multi-language scanner skeleton (TS/Go/Python/Proto)
- shared-proto: buf v2 + classes.proto (ClassService CRUD contract)
- api-gateway: Go/Gin + JWT HS256 auth + reverse proxy + request ID
- classes: NestJS golden template (error system + observability + middleware + CRUD + tests)
- teacher-portal: Next.js + paper-feel UI design system
- CI/CD: 4 workflows (go/ts/py/proto)
- docs: migration guide + project_rules + coding-standards + git-workflow + ui-design-system + 004 + 9 module READMEs + known-issues + spec/plan migration + roadmap

.gitignore

@@ -0,0 +1,65 @@
+# Dependencies
+node_modules/
+.pnpm-store/
+
+# Build outputs
+dist/
+build/
+.next/
+out/
+*.tsbuildinfo
+target/
+bin/
+obj/
+
+# Go
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+*.test
+*.out
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+.venv/
+venv/
+*.egg-info/
+
+# Environment
+.env
+.env.local
+.env.*.local
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+logs/
+
+# Database
+*.db
+*.sqlite
+arch.db
+
+# Test coverage
+coverage/
+.nyc_output/
+
+# Docker
+docker-compose.override.yml
+
+# Temp
+tmp/
+temp/