fix(security): allow wss:// to Clerk in CSP connect-src

Clerk's client SDK opens a WebSocket to the frontend API for session
sync; the CSP only allowed https:// to that origin, silently breaking
login (blank page, "Connection closed" exception) once enforced.

next.config.ts

@@ -26,6 +26,7 @@ function buildCsp(): string {
     "connect-src": [
       "'self'",
       "https://clerk.pawfeed.org",
+      "wss://clerk.pawfeed.org",
       "https://accounts.pawfeed.org",
       supabase,
       "https://stream.mux.com",