feat: recover missing conversations, fix media attachment, add manual inbox tab

Missing conversations: recipient Reddit accounts that are deleted or suspended
left conversations unaccounted for. A new RecipientAccountStatusService polls
Reddit for the users behind cached conversations and records their account
status durably, with progressive backfill and delta-media fixes in ChatService
so history and images are no longer dropped mid-sync.

Media: attachMedia now surfaces download failures as MediaAttachmentError so the
sync cursor can be retried instead of silently losing an image, recognizes image
bytes when Matrix returns a generic content type, and keeps separate gallery
occurrences when the same asset appears in more than one event.

Manual inbox tab: the conversations list now carries the reply-loop status, so
the inbox can separate conversations the operator is driving by hand from the
ones automation is still handling. A Manual filter pill and a per-row chip
explain why each conversation was handed over.

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

tests/account-repositories.test.ts

@@ -6,6 +6,7 @@ import path from 'node:path';
 import {
   AccountContentRepository,
   RedditAccountsRepository,
+  RedditRecipientAccountStatusRepository,
 } from '../src/database/account-repositories.js';
 import { LEGACY_UNASSIGNED_ACCOUNT_ID, runMigrations } from '../src/database/client.js';
 import { importLegacyAccountContent } from '../src/database/legacy-content-import.js';
@@ -54,6 +55,15 @@ describe('multi-account database ownership', () => {
     });
   });
 
+  it('stores recipient account state case-insensitively and allows later recovery', () => {
+    const statuses = new RedditRecipientAccountStatusRepository(db);
+    statuses.upsert('Alice', 'deleted', 100);
+    expect(statuses.get('alice')).toEqual({ username: 'Alice', status: 'deleted', checkedAt: 100 });
+
+    statuses.upsert('ALICE', 'active', 200);
+    expect(statuses.get('alice')).toEqual({ username: 'Alice', status: 'active', checkedAt: 200 });
+  });
+
   it('updates matrix credentials in place without touching cookies or status', () => {
     addAccount('t2_alice', 'alice-bot', 100);
 
@@ -196,4 +206,19 @@ describe('multi-account database ownership', () => {
       fs.rmSync(dataDirectory, { recursive: true, force: true });
     }
   });
+
+  it('stores separate media occurrences that share one downloaded file', () => {
+    addAccount('t2_alice', 'alice-bot', 100);
+    const base = {
+      accountId: 't2_alice', chatUsername: 'sender', chatRoomId: 'room-one', sender: 'sender',
+      originalUrl: 'mxc://reddit.com/shared', fileName: 'shared.jpg', relativePath: 'shared.jpg',
+      createdAt: 10,
+    };
+
+    content.upsertMedia({ ...base, mediaId: 'event-one', timestamp: 1 });
+    content.upsertMedia({ ...base, mediaId: 'event-two', timestamp: 2 });
+
+    expect(content.listMedia('t2_alice')).toHaveLength(2);
+    expect(content.getMediaByOriginalUrl('t2_alice', base.originalUrl)?.mediaId).toBe('event-one');
+  });
 });