P1: Wire didReceivePendingFileTransfer into ChatViewModel
- Add implementation that creates system message for pending files
- Route to appropriate chat (public/private)
- Send local notification for incoming files
- Auto-decline files from blocked users
P2: Keep pending files in queue if save fails
- Only remove file from pendingFiles after successful save
- Allows user to retry accept if initial save failed
Also adds test for save failure scenario.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Incoming files are now held in memory via PendingFileManager instead of
being auto-saved to disk. Users must explicitly accept files before they
are written. This prevents attackers from exhausting device storage.
Key changes:
- Add PendingFileManager with configurable limits (max 10 files, 5MB total)
- Files auto-expire after 5 minutes if not accepted
- LRU eviction when limits are exceeded
- Pending files cleared during panic mode (emergencyDisconnectAll)
- Add didReceivePendingFileTransfer delegate method
- Add acceptPendingFile/declinePendingFile to Transport protocol
Security audit reference: Cure53 BCH-01-002 (Medium severity)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
