P3.2 · Sync orchestrator + conflict detection

What

Central coordinator between pull and push. Maintains a SyncStateCache:

type SyncState = {
  linearId: string;
  lastSyncedAt: string;            // ISO timestamp
  lastKnownRemoteBody: string;     // for diff
  lastKnownLocalBody: string;      // for diff
  lastKnownRemoteUpdatedAt: string;
};

Conflict detection algorithm

On every sync tick:

1. Fetch issues updated since min(lastSyncedAt across all notes).
2. For each returned issue, compare:
   • Was local modified since lastSyncedAt? (check Obsidian file mtime vs lastSyncedAt)
   • Was remote modified since lastSyncedAt? (issue.updatedAt > lastSyncedAt)
3. Four cases:
   • Neither changed → no-op
   • Only remote changed → pull (apply remote to local)
   • Only local changed → push (apply local to remote)
   • Both changed → conflict
4. Conflict routing:
   • If |remoteUpdatedAt - localModifiedAt| < 24h → last-write-wins (newer timestamp wins), log a Notice.
   • Otherwise → queue for conflict UI (P3.3).

Acceptance criteria

• Integration test with a simulated remote-then-local edit produces the correct route for all four cases.
• Last-write-wins path works silently for near-simultaneous edits.
• Conflicts are queued, not auto-resolved when >24h divergence.