feat: public events/polls, friends graph, captcha, SSE hardening, and admin UX

Ship product gaps: register/vote pages, friend add/accept/decline/remove, email verify TTL, captcha on login/forgot, soft-fail user actions, SSE abort/shared client, Commando Centrum error toasts, admin delete for events/polls, and IT/NL i18n fills.

Co-authored-by: Cursor <[email protected]>

src/app/api/radio/stream/route.ts

@@ -64,7 +64,6 @@ export async function GET(req: Request) {
 			"content-type": "text/event-stream; charset=utf-8",
 			"cache-control": "no-store, no-transform",
 			connection: "keep-alive",
-			"access-control-allow-origin": "*",
 		},
 	});
 }