fix: chat WS relay URL + chat UX improvements

- Fix docker-compose to read GATEWAY_WS_URL (was VITE_WS_URL, never set)
- Fix gateway-relay.ts default to ws.hammer.donovankelly.xyz
- Fix Elysia TS errors in error handlers (cast to any)
- Add thinking/typing indicator in chat (bouncing dots)
- Add message timestamps (tap to show)
- Add thread renaming (double-click thread name)
- Auto-resize chat input textarea

backend/src/index.ts

@@ -140,7 +140,7 @@ const app = new Elysia()
 
   .get("/health", () => ({ status: "ok", service: "hammer-queue" }))
   .onError(({ error, set }) => {
-    const msg = error?.message || String(error);
+    const msg = (error as any)?.message || String(error);
     if (msg === "Unauthorized") {
       set.status = 401;
       return { error: "Unauthorized" };