fix(ingestion): address the #344 review (history re-check, keys, repair)

- Images without an embedded API graph: the scan now asks recorded
  history before skipping a file with no prompt metadata, and the monitor
  gives a keyless unlinked image one history-only re-check when its run's
  outputs are recorded (a seal notification from the outputs write; at
  most 1000 waiting images, each for an hour).
- Run keys: an image is unkeyable when any positive node has no key, so a
  two-pass graph is never linked through the other pass; links follow
  ComfyUI's is_link exactly.
- A failed save marks the node's run key like an empty editor, so an
  older entry of that key can't stand in for this run.
- A placeholder is the latest entry: the image stays unlinked without
  falling through to history, the same rule as a popped placeholder.
- An index on execution_run_outputs(filename, subfolder, root_key,
  path_style) for the history lookup, added by migration and accepted by
  the output schema check (any other index is still refused).
- Repair tool: unlink removes only the link record and only while the
  image is still linked to the prompt it was judged on; every run prints
  what --apply does.
- Real-host case proves the re-run's PromptManager node was cached.

database/execution_outputs.py

@@ -4,6 +4,8 @@ import sqlite3
 from contextlib import ExitStack
 from typing import Callable, ContextManager
 
+from .run_attribution import notify_outputs_sealed
+
 try:
     from ..utils.execution_history_events import RunFinish, encode_command
     from ..utils.execution_outputs import OutputBundle, validate_output_bundle
@@ -113,6 +115,10 @@ class ExecutionOutputOperations:
                     "VALUES(?,?,?,?,?,?,?,?)",
                     [(run_id, *reference) for reference in prepared],
                 )
+        # Committed: images waiting for this run may now be attributed (#342)
+        notify_outputs_sealed(
+            run_id, [dict(zip(_REFERENCE_FIELDS, row)) for row in prepared]
+        )
         return True
 
     def get_execution_outputs(self, run_id: str) -> dict: