context_facts, context_documents, and context_chunks now live in
turnstone-context.db (sibling of turnstone.db). The glean scheduler
held write locks on the main DB long enough to cause 5-second timeout
failures on context fact inserts; separate files have independent WAL
write locks so they never contend.
Changes:
- pipeline.py: extract _CONTEXT_SCHEMA + ensure_context_schema()
- rest.py: CONTEXT_DB_PATH (TURNSTONE_CONTEXT_DB env var, defaults to
sibling file); init via ensure_context_schema(); all context routes
pass CONTEXT_DB_PATH; diagnose_stream receives context_db_path kwarg
- diagnose/__init__.py: diagnose_stream() accepts context_db_path
(falls back to db_path for backward compat); retrieve_context uses it
- store.py: sqlite3.connect() timeout=30.0 — Python driver retry loop
is independent of PRAGMA busy_timeout; needed for any remaining
contention during test or single-file deployments
Closes: #42
