Tightens verifier consistency, closes test gaps, hardens the fire-and-forget
eviction snapshot, and routes the new concurrency knob through Settings.
- Pre-flight ``int()`` guard in ``_verify_notes`` mirrors ``_verify_deck_cards``,
so a non-numeric note id produces a type-specific log line instead of
falling through to the generic "unexpected error" branch.
- Adds explicit 403 tests for the file and news verifiers (symmetry with the
existing notes/deck 403 tests) plus a ``non_numeric_id_keeps`` test.
- ``AppContext`` and ``OAuthAppContext`` no longer snapshot
``_vector_sync_state.eviction_task_group`` at lifespan-yield time. Both
expose it as a ``@property`` that reads the singleton dynamically, removing
the order-sensitive race where a future startup-ordering change could
silently degrade fire-and-forget eviction to inline forever.
- Adds ``verification_concurrency`` (env var ``VERIFICATION_CONCURRENCY``,
default 20) to ``Settings`` with a dynaconf validator; ``verify_search_results``
resolves the cap lazily from settings when the caller doesn't override it.
- Enriches the news verifier TODO to call out that ``batch_size=-1`` is
intentional — a numeric ceiling would silently break correctness because
any item beyond the cap would be missing from ``present_ids`` and dropped.
- Updates ``Optional[TaskGroup]`` to ``TaskGroup | None`` per project style.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
