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>

src/services/reddit-account-runtime.ts

@@ -6,6 +6,7 @@ import type {
   RedditAccountPrivateRecord,
   RedditAccountsRepository,
   AccountContentRepository,
+  RedditRecipientAccountStatusRepository,
 } from '../database/account-repositories.js';
 import type {
   ConversationOutcomesRepository,
@@ -33,6 +34,7 @@ import type { ProcessorService } from './processor.js';
 import type { ResponseCheckerService } from './response-checker.js';
 import type { RedditPost } from '../reddit/api.js';
 import type { ConversationAutomationService } from './conversation-automation.js';
+import type { RecipientAccountStatusService } from './recipient-account-status.js';
 import type { ProcessedPost, ProcessResult } from './processor.js';
 
 /** Credentials passed to a factory. They must never be exposed by list/snapshot APIs. */
@@ -70,6 +72,7 @@ export interface RedditAccountRuntimeResources {
   conversationOutcomesRepo: ConversationOutcomesRepository;
   redditUsersRepo: RedditUsersRepository;
   accountContentRepo: AccountContentRepository;
+  recipientAccountStatusRepo: RedditRecipientAccountStatusRepository;
   activityLogRepo: ActivityLogRepository;
 
   monitorService: MonitorService;
@@ -79,6 +82,7 @@ export interface RedditAccountRuntimeResources {
   chatService: ChatService;
   mediaService: MediaService;
   mediaSyncService: MediaSyncService;
+  recipientAccountStatusService: RecipientAccountStatusService;
   mediaExchange?: MediaLibraryExchangeService;
   rateLimiter: RateLimiter;
 }