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/admin/settings/cms-settings-config.ts

@@ -241,6 +241,14 @@ export const SETTINGS_GROUPS: SettingsGroup[] = [
 				type: "boolean",
 				defaultValue: "0",
 			},
+			{
+				key: "require_email_verification",
+				label: "Require email verification",
+				description:
+					"Block login until the account email is verified (accounts without email are unaffected).",
+				type: "boolean",
+				defaultValue: "0",
+			},
 			{
 				key: "max_accounts_per_ip",
 				label: "Max accounts per IP",