Initial scaffold: Go backend, React frontend, Docker Compose

- Go backend: config, db (PostgreSQL migrations), auth (argon2id + sessions),
  middleware (cookie sessions, RequireAuth), chi router, cmd/server
- React frontend: Vite + React 18 + TS + Tailwind + Gruvbox palette + terminal CSS
- Docker: compose.yml (Postgres, Valkey, minio, LiveKit, coturn, Caddy),
  livekit.yaml, Caddyfile, Dockerfile (multi-stage Go+Node+Alpine)
- .env.example, .gitignore, README.md

docker/livekit.yaml

@@ -0,0 +1,16 @@
+port: 7880
+bind: 0.0.0.0
+rtc:
+  tcp_port: 7881
+  udp_port: 7882
+  use_external_ip: true
+  relay_range_start: 50000
+  relay_range_end: 50100
+turn:
+  enabled: true
+  domain: livekit.localhost
+  tls_port: 5349
+  udp_port: 3478
+  external_tls: false
+keys:
+  devkey: secret