Quality contract red on main: zip strict=, format drift, and typecheck narrowing (CI cancelled since 6db5c2b3)

[alexeygrigorev]

What happened

The push of d7e53f5f (merge of #382) went red:

• CI run 35010874544: quality job failed; its fail-fast step cancelled django, playwright, and container; ci-gate failed → run cancelled.
• Deploy Dev run 35010874633: verify-ci (requires a green CI verdict for the exact SHA) failed → publish/deploy skipped.

Main has therefore had no green release pipeline since the run for 55a400c7 (15:56Z); the intervening runs for b297191d and d7e53f5f died in the quality job.

Root causes (all in the versioned quality contract, target order)

1. lint — B905 zip() without explicit strict= at courses/tests/test_course_illustrations.py:127, introduced by 6db5c2b3 (no issue reference).
2. format-check (would have failed next) — drift in content/sync_parsers/podcasts.py and content/tests/test_sync_parsers.py (via the D2.2b Content sync adoption: podcast and books #382 merge) and courses/tests/test_family_page_content.py.
3. typecheck (would have failed next) — 3 mypy errors from dict | None not narrowed after assertIsNotNone in content/tests/test_faq.py:405,417 and courses/tests/test_course_family_landing.py:425.

Fix (on-call, this issue)

• strict=True on the flagged zip (both iterables have length 3; mispairing would silently build wrong fixtures).
• ruff format applied to the four drifted files.
• Bare assert x is not None narrowing lines added after the three assertIsNotNone calls (matches the existing pattern in content/tests/test_queries.py).

Verified locally: python -m ci.quality_contract --repository . passes end-to-end (lint, format 832 files, typecheck, migrations, django-check, deployment-check, test-ci 671 passed).

Refs the introducing commit 6db5c2b3; also hardens files touched by #382.