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/media.test.ts

@@ -2,7 +2,7 @@ import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import fs from 'fs/promises';
 import os from 'os';
 import path from 'path';
-import { MediaService } from '../src/services/media.js';
+import { MediaAttachmentError, MediaService } from '../src/services/media.js';
 import type { MediaDownloader } from '../src/services/media.js';
 import type { ActiveChat, ChatMessage } from '../src/services/chat.js';
 import { createMockLogger } from '../tests/mockLogger.js';
@@ -47,11 +47,24 @@ describe('MediaService', () => {
   });
 
   describe('resolveFullMediaUrl', () => {
-    it('converts blurred thumbnail to full resolution', () => {
+    it('falls back to the blurred thumbnail when the full-resolution response is not an image', async () => {
       const blurred = 'https://matrix.redditspace.com/_matrix/media/v3/thumbnail/reddit.com/blur_XXXXX?height=300';
-      // We can't test private method directly, but we can test via attachMedia
-      // For now, verify the service is created
-      expect(service).toBeDefined();
+      const fetch = vi.fn()
+        .mockResolvedValueOnce({ buffer: Buffer.from('not an image'), contentType: 'text/html' })
+        .mockResolvedValueOnce({ buffer: Buffer.from('image data'), contentType: 'image/jpeg' });
+      service = new MediaService({ fetch }, logger, tempDir);
+
+      const [message] = await service.attachMedia(createMockChat(), [{
+        eventId: '$blurred', sender: 'user1', text: '', timestamp: 1, isSelf: false,
+        mediaUrls: [blurred],
+      }]);
+
+      expect(fetch).toHaveBeenNthCalledWith(
+        1,
+        'https://matrix.redditspace.com/_matrix/media/v3/download/reddit.com/XXXXX',
+      );
+      expect(fetch).toHaveBeenNthCalledWith(2, blurred);
+      expect(message.media).toHaveLength(1);
     });
 
     it('leaves non-thumbnail URLs unchanged', () => {
@@ -109,7 +122,7 @@ describe('MediaService', () => {
       expect(result[0].media).toBeUndefined();
     });
 
-    it('handles download failures gracefully', async () => {
+    it('surfaces download failures so the sync cursor can be retried', async () => {
       const failingDownloader = createMockDownloader(null);
       service = new MediaService(failingDownloader, logger);
 
@@ -118,8 +131,7 @@ describe('MediaService', () => {
         { sender: 'user1', text: 'Test', timestamp: Date.now(), isSelf: false, mediaUrls: ['http://example.com/img.jpg'] },
       ];
 
-      const result = await service.attachMedia(chat, messages);
-      expect(result[0].media).toBeUndefined();
+      await expect(service.attachMedia(chat, messages)).rejects.toBeInstanceOf(MediaAttachmentError);
     });
 
     it('caches downloaded media by URL hash', async () => {
@@ -147,6 +159,39 @@ describe('MediaService', () => {
       expect(downloader.fetch).not.toHaveBeenCalled();
     });
 
+    it('keeps separate gallery occurrences when the same asset appears in separate events', async () => {
+      const chat = createMockChat();
+      const url = 'http://example.com/reused.jpg';
+
+      await service.attachMedia(chat, [
+        { eventId: '$one', sender: 'user1', text: 'First', timestamp: 1, isSelf: false, mediaUrls: [url] },
+        { eventId: '$two', sender: 'user1', text: 'Second', timestamp: 2, isSelf: false, mediaUrls: [url] },
+      ]);
+
+      const items = await service.getMediaItems();
+      expect(items).toHaveLength(2);
+      expect(new Set(items.map((item) => item.id)).size).toBe(2);
+      expect(new Set(items.map((item) => item.relativePath)).size).toBe(1);
+      expect(downloader.fetch).toHaveBeenCalledTimes(1);
+    });
+
+    it('recognizes image bytes when Matrix returns a generic content type', async () => {
+      const png = Buffer.from(
+        'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII=',
+        'base64',
+      );
+      service = new MediaService({
+        fetch: vi.fn(async () => ({ buffer: png, contentType: 'application/octet-stream' })),
+      }, logger, tempDir);
+
+      const [message] = await service.attachMedia(createMockChat(), [{
+        eventId: '$generic-mime', sender: 'user1', text: '', timestamp: 1, isSelf: false,
+        mediaUrls: ['mxc://example.test/no-extension'],
+      }]);
+
+      expect(message.media?.[0].fileName).toMatch(/\.png$/);
+    });
+
     it('processes multiple messages', async () => {
       const chat = createMockChat();
       const messages: Array<ChatMessage & { mediaUrls: string[] }> = [