[nycomp]

What

Resolves every pyright diagnostic (#95) and adds a pyright job to .github/workflows/python-tests.yml following the nyxchange-timetable-v2 pattern (pyright as a dev dependency, poetry run pyright).

At HEAD of main, pyright 1.1.414 reported 55 errors (the issue counted 23; PRs #96–#108 added code since). After this PR: 0 errors, 0 warnings, and all 291 unit tests pass.

Source fixes (campus_python/)

• None-guards on Optional values: LoginSession.user_id is UserID | None; the credentials lookups in _get_token_from_session and the auth token getter now raise AuthenticationError when it is None instead of indexing with a possible None. push_context skips the users-route fallback (and the cache put) when there is neither an embedded user nor a user id.
• 401 hook feature-detect: with_user_session now installs the unauthorized hook via isinstance(client, CampusRequest) — matching the documented JsonClient contract ("callers must feature-detect") instead of assuming every client has the optional capability.
• env.get(...) or "" after env.require("AUDIT_API_KEY") (require guarantees presence but returns None).
• Retry-After parsing (audit/ratelimit.py): explicit None-check instead of relying on float(None) raising TypeError.
• Payload typing: assignments.new() payload annotated dict[str, object].
• Removed the dead pre-#857 fallback import of HttpHeader from campus.model in json_client — the lock now resolves campus-suite past the webauth move, so the fallback branch can never run and no longer type-checks.

Test fixes (tests/unit/)

• MagicMock/cast where runtime swaps real objects for mocks (_session, client.post, _users accessed through stored mock references instead of the typed properties).
• None-narrowing asserts after assertIsNotNone (pyright does not narrow through unittest assertions).
• fake_send(prepared=…) renamed to request to match the Session.send signature.
• Rule-scoped # pyright: ignore[reportCallIssue] / [reportMissingImports] on deliberate-negative pins (constructor-must-reject kwargs, the sys.path-shimmed errors import).

Verification

• poetry run pyright — 0 errors, 0 warnings (pyright 1.1.414 via ^1.1.400 dev dep).
• poetry run pytest — 291 passed.

Fixes #95