Fix temporal_next edges: wire link_temporal_next into capture path, fix events_query decryption

- capture.py: call link_temporal_next() after store.insert() in capture_turn()
- retrieve.py: call link_temporal_next() in contradict() for contradict inserts
- qdrant_store.py: events_query() was json.loads() on encrypted data_json,
  losing record_id — pass raw string so query_events() can decrypt it

src/iai_mcp/capture.py

@@ -201,6 +201,13 @@ def capture_turn(
         log.exception("capture_turn insert failed")
         return {"status": "skipped", "record_id": None, "reason": f"insert-failed: {type(e).__name__}"}
 
+    # Wire temporal_next: link this insert to the previous same-session insert.
+    try:
+        from iai_mcp.retrieve import link_temporal_next
+        link_temporal_next(store, rec, session_id=session_id)
+    except Exception:
+        pass  # diagnostic only; never block the write path.
+
     return {"status": "inserted", "record_id": str(rec.id), "reason": f"tier={tier}"}