feat: bootstrap MediaStationGo (Go + React rewrite of MediaStation)

Adopt the cropflre/nowen-video tech stack and rebuild the project from
scratch:

  - Backend: Go 1.25 + Gin + GORM + SQLite (WAL) + JWT + WebSocket hub.
    Layered packages config / database / model / repository / service /
    middleware / handler. Default admin (admin/admin123) seeded on first
    run; /api routes for auth, libraries, media, stream and admin
    panels. WebSocket scan-progress events at /api/ws.
  - Frontend: React 18 + Vite 5 + Tailwind 3.4 + Zustand + axios +
    react-router 6 + lucide-react + framer-motion + hls.js. Pages for
    Login / Home / Library / Search / MediaDetail / Player / Admin
    (Library, Users, Settings tabs).
  - Distribution: multi-arch Dockerfile (frontend -> backend -> Alpine
    runtime), docker-compose.yml, GitHub Actions for CI and GHCR
    publish, Makefile, env-prefixed config (MEDIASTATION_*).
  - Docs: README, CONTRIBUTING, .env.example, config.example.yaml.

Backend builds, vets and tests pass. Frontend builds via tsc -b && vite
build (250 kB JS / 16 kB CSS, gzipped 84 / 4 kB).

.gitignore

@@ -0,0 +1,47 @@
+# Binaries
+bin/
+*.exe
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+*.out
+
+# Go workspace
+go.work
+
+# Dependency directories
+node_modules/
+
+# Build artifacts
+web/dist/
+web/.vite/
+web/coverage/
+web/tsconfig.tsbuildinfo
+
+# Data / runtime
+data/
+cache/
+logs/
+*.log
+*.db
+*.db-journal
+*.db-shm
+*.db-wal
+
+# Editor / OS
+.idea/
+.vscode/
+.DS_Store
+Thumbs.db
+
+# Env files
+.env
+.env.local
+.env.*.local
+
+# Local configs (keep examples)
+config/secrets.yaml
+config.yaml