news: DeepSeek validation, vs_forecast fix, /status source health

Validation (llm_news_eval.py harness + 78-headline golden CSV + verdict
doc): headline scoring 78/78 vs keyword baseline 24/78 — validated;
event gold-direction calls misread close K/M numeric comparisons ~11%
of the time (both claims cases in sample, JOLTS 8.79M vs 8.84M).

Fix: event payload now carries code-computed "vs_forecast" (from
EconomicEvent.surprise) and the prompt gains an explicit inverted-
metrics rule + worked claims example — iteration 1 (field alone) fixed
the arithmetic but exposed a masked inversion error. 18/18 on live
re-verification (4 misreads fixed, 11 regression cases clean, 3 fresh
both-side probes).

/status: new "News & AI" section — per-source health for the calendar
chain (which of FF/MyFXBook served), each RSS feed, and DeepSeek
(daily count, last error kind), written passively by the existing
fetch paths under _cache_lock. Failures WARN once on transition
(repeats DEBUG, recovery INFO) so the rotating log carries outage
stories without 10-min spam.

test_all.py: +5 Module 19 tests (351 total); also carries the Module 22
fixed-RR-TP tests from the prior research session (shared file).
Replay artifacts dir gitignored like commit_ladder.

Claude-Session: https://claude.ai/code/session_017mbXs9HRawZhD1uZ3ze7zQ

.gitignore

@@ -36,3 +36,4 @@ backtest/__pycache__/
 .env.*
 logs/
 backtest/research/commit_ladder_2026-08/
+backtest/research/llm_news_eval_2026-08/