* fix(gdelt): publish enriched copies instead of mutating live features
_enrich_gdelt_titles_background ran in a daemon thread that mutated the
nested properties dicts of GDELT features already published into
latest_data[gdelt]. HTTP readers hold live references to those dicts and
serialize them outside the data lock, so the in-place mutation raced the
serializer and raised RuntimeError: dictionary changed size during
iteration on /api/live-data/slow and /api/bootstrap/critical.
Enrich deep copies instead and atomically swap the top-level key under
_data_lock, with an identity guard so a newer fetch_gdelt() is not clobbered.
Honors the replace-don't-mutate contract documented in fetchers/_store.py.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* test(gdelt): regression test for background enrichment isolation
Asserts _enrich_gdelt_titles_background does not mutate already-published features and instead atomically swaps latest_data["gdelt"] with enriched copies (with the identity guard). Locks in the fix for the dictionary-changed-size race.
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Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
