chore(v2): lint pass — black + ruff auto-fix + mypy regressions (#29 v1.1)

Pre-merge lint hygiene on the PR #30 touched files:

- `black` reformatted 9 files (cassette_transport, crud, models, tasks,
  views_api, nip44, all 3 cassette test files, migrations). Cosmetic:
  line lengths, trailing commas, multi-line argument layout.
- `ruff check --fix` cleared 176 of 202 errors auto-fixed. Mostly
  `UP006` `typing.Optional` → `| None` modernization, `I001` import
  sort order, `UP035` typing-extensions cleanup.
- Two new mypy regressions introduced by the migration commit dcb7de0
  fixed:
  - `crud.py:apply_bootstrap_state` — annotated `existing_first: dict
    | None` on the dedup fetch.
  - `tasks.py:_cassette_consumer_tick` — `# type: ignore[arg-type]` on
    the `nostr_client.relay_manager.add_subscription` call; nostrclient's
    upstream typing declares `list[str]` for filters but the actual
    Nostr protocol takes `list[<filter-dict>]`. The runtime accepts it
    (live smoke at 13:43Z dispatched `nip44_decrypt` cleanly through
    this subscription); the typing mismatch is upstream's.

Remaining lint state, intentionally not addressed in this commit
(all pre-existing baseline, not regressions):
- 8 mypy errors in `calculations.py` + the unchanged-by-this-PR parts
  of `crud.py` — pre-existing on v2-bitspire.
- 26 ruff style warnings: 14 are N805 false-positives on Pydantic
  validators (`cls` first-arg is correct for `@validator`-decorated
  methods); 4 are N818 exception-name-suffix preferences on my new
  exception classes (renaming would touch many call sites; keep
  `OperatorIdentityMissing` / `SignerUnavailable` / `RelayUnavailable`
  / `_NostrclientUnavailable` as-is for clarity); 5 are E501 line-too-
  long on docstrings (the long lines are formatted for clarity);
  1 RUF002 unicode-minus in a docstring.

Tests: 155 passed, 1 pre-existing async-plugin failure unchanged.
Live smoke (both publish + consume directions through the bunker)
unaffected — this is purely a code-style pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

views_api.py

@@ -872,9 +872,7 @@ async def api_publish_machine_cassettes(
         updated = await update_cassette_config(
             machine_id,
             pos,
-            UpsertCassetteConfigData(
-                denomination=row.denomination, count=row.count
-            ),
+            UpsertCassetteConfigData(denomination=row.denomination, count=row.count),
             updated_by=user.id,
         )
         if updated is None:
@@ -894,8 +892,6 @@ async def api_publish_machine_cassettes(
     except RelayUnavailable as exc:
         raise HTTPException(HTTPStatus.SERVICE_UNAVAILABLE, str(exc)) from exc
     except CassetteTransportError as exc:
-        raise HTTPException(
-            HTTPStatus.INTERNAL_SERVER_ERROR, str(exc)
-        ) from exc
+        raise HTTPException(HTTPStatus.INTERNAL_SERVER_ERROR, str(exc)) from exc
 
     return await list_cassette_configs_for_machine(machine_id)