Initial commit: RehearsalHub POC

Full-stack self-hosted band rehearsal platform:

Backend (FastAPI + SQLAlchemy 2.0 async):
- Auth with JWT (register, login, /me, settings)
- Band management with Nextcloud folder integration
- Song management with audio version tracking
- Nextcloud scan to auto-import audio files
- Band membership with link-based invite system
- Song comments
- Audio analysis worker (BPM, key, loudness, waveform)
- Nextcloud activity watcher for auto-import
- WebSocket support for real-time annotation updates
- Alembic migrations (0001–0003)
- Repository pattern, Ruff + mypy configured

Frontend (React 18 + Vite + TypeScript strict):
- Login/register page with post-login redirect
- Home page with band list and creation form
- Band page with member panel, invite link, song list, NC scan
- Song page with waveform player, annotations, comment thread
- Settings page for per-user Nextcloud credentials
- Invite acceptance page (/invite/:token)
- ESLint v9 flat config + TypeScript strict mode

Infrastructure:
- Docker Compose: PostgreSQL, Redis, API, worker, watcher, nginx
- nginx reverse proxy for static files + /api/ proxy
- make check runs all linters before docker compose build

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/hooks/useWebSocket.ts

@@ -0,0 +1,40 @@
+import { useEffect, useLayoutEffect, useRef } from "react";
+
+type WsEvent = { event: string; data: unknown };
+type EventHandler = (data: unknown) => void;
+
+export function useVersionWebSocket(
+  versionId: string | null,
+  handlers: Record<string, EventHandler>
+) {
+  const handlersRef = useRef(handlers);
+  useLayoutEffect(() => {
+    handlersRef.current = handlers;
+  });
+
+  useEffect(() => {
+    if (!versionId) return;
+    const protocol = window.location.protocol === "https:" ? "wss" : "ws";
+    const ws = new WebSocket(`${protocol}://${window.location.host}/ws/versions/${versionId}`);
+
+    ws.onmessage = (evt) => {
+      try {
+        const msg: WsEvent = JSON.parse(evt.data);
+        handlersRef.current[msg.event]?.(msg.data);
+      } catch {
+        // ignore malformed messages
+      }
+    };
+
+    const pingInterval = setInterval(() => {
+      if (ws.readyState === WebSocket.OPEN) {
+        ws.send(JSON.stringify({ event: "ping" }));
+      }
+    }, 30_000);
+
+    return () => {
+      clearInterval(pingInterval);
+      ws.close();
+    };
+  }, [versionId]);
+}