remove the AI market-outlook feature (delivery-side only; books byte-identical)

Owner decision 2026-09-15. Gone: market_outlook.py, the post-H1-scan Telegram
outlook DM, main.py --outlook, the outlooks table DDL/migration/writer in
signal_log.py, the market_outlook config block + MARKET_OUTLOOK_ENABLED, and
test Module 26. Last commit containing the feature: 2836024.

- app_config: "market_outlook" stays in _KNOWN_TOP as a TOLERATED, ignored
  legacy key (oanda.account_id precedent) with one warning, so a live
  config.json that still carries the block keeps booting.
- signal_log: existing DBs keep their orphan outlooks table and rows (no
  DROP TABLE); fresh DBs never create it.
- tests: Module 26's 4-thread concurrent legacy-DB migration test (the
  suite's only one) moved to Module 31; new test for the tolerated block.
  519 -> 509 tests, 34 -> 33 modules, 0 failed.
- docs: CLAUDE.md usage/config/file-map lines and a dated state note.

Verification: W2 books (2024-09-05 -> 2026-09-05, $0.65, NumPy CPU, 0 cache
fallbacks) byte-identical before/after — M5 29120a1ee32979431d062f210d41a9d1
(781 / +146.07R / PF 1.52), M15 d185f099482a07f29502cb5a371a9bbf
(931 / +146.14R / PF 1.43).

news_engine.py

@@ -438,7 +438,7 @@ class NewsEngine:
             # here rather than in the fetch so the class-level cache and
             # the feed-health counts still describe what the feeds sent;
             # every consumer (aggregate score, summary, dashboard, panel,
-            # outlook, signal log) reads context.news_headlines.
+            # signal log) reads context.news_headlines.
             kept = [h for h in headlines if not _is_neutral_headline(h)]
             if len(kept) != len(headlines):
                 logger.debug(