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/Caddyfile

@@ -0,0 +1,23 @@
+{
+    auto_https off
+}
+
+:80 {
+    handle_path /api/* {
+        reverse_proxy app:8080
+    }
+
+    handle_path /ws {
+        reverse_proxy app:8080
+    }
+
+    handle_path /livekit/* {
+        reverse_proxy livekit:7880
+    }
+
+    handle {
+        root * /srv/web
+        try_files {path} /index.html
+        file_server
+    }
+}