Adds two new flags to the backfill script:
* --re-embed-all walks **every** memory (not just those without
an existing embeddings row) and re-emits embedding_indexed
events. The projector is INSERT OR REPLACE, so re-emitting an event
for an existing memory replaces the prior vector. Use this when
swapping embedding models — the default mode still keeps the Phase
4 gap-fill behavior.
* --model M overrides Settings.embedding_model for this run.
The script also gains a small _build_client helper that returns
None for the pseudo path (no client needed) and a FeatherlessClient
otherwise; tests monkeypatch this to inject a Mock with canned
embeddings.
Adds tests/test_backfill_embeddings.py with three integration
tests: re-embed-all walks every memory, default mode skips existing
rows, and --model overrides the configured model end-to-end.
Joseph Doherty
9b7a6d459f