feat: flag accounts Reddit considers unestablished and re-test them

New accounts cannot start chats until Reddit considers them established.
Until now the bot would burn a candidate on every invitation Reddit was
always going to reject, with nothing in the dashboard explaining why the
account looked idle.

Two signals feed the verdict. A periodic profile check reads the
account's own age, karma and email verification from about.json and
compares them against configurable thresholds — that is what flags a
brand new account before it wastes anything. A rejected invitation is
authoritative: Reddit has told us directly, so the account is held out of
sending with a backoff that doubles per rejection, and a delivered
invitation clears the flag outright.

An unestablished account takes no new posts (canAcceptPost), raises an
attention item, reports an `unestablished` sending state, and shows its
age/karma evidence on the Accounts page. An unchecked account is always
allowed through, so a first run is never blocked.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/bootstrap.ts

@@ -43,7 +43,11 @@ import { PushNotifier } from './services/push-notifier.js';
 import { RedditSessionImporter } from './services/reddit-session-importer.js';
 import { AccountAuthContext, authenticateCurrentAccount } from './services/account-auth-context.js';
 import { ConfigStore } from './config/persistence.js';
-import { RedditAccountsRepository, AccountContentRepository } from './database/account-repositories.js';
+import {
+  RedditAccountsRepository,
+  AccountContentRepository,
+  RedditAccountEstablishmentRepository,
+} from './database/account-repositories.js';
 import { RedditAccountsService } from './services/reddit-accounts.js';
 import type { Cookie } from 'playwright';
 import { ChatCache } from './services/chat/cache.js';
@@ -371,6 +375,7 @@ export async function bootstrap(
     accountAuth,
     accountRuntimeManager,
     browserClient,
+    new RedditAccountEstablishmentRepository(db),
   );
   if (config.web.enabled) {
     webServer = new WebServer(