copybot: per-niche FAK re-quote waits from measured crater-refill times

The flat 10s retry was calibrated to nothing; the tape now says craters
refill at very different speeds (research requote_timing, 775k crater
prints): crypto 94% within 4s, esports 83% within 10s, sports only 70% at
10s but 76% by 25s, geo/politics tails run minutes (price guard is the
protection there, not the retry). Waits move to FAK_RETRY_NICHE_DEFAULT
{crypto 4, esports 10, sports/geo/politics/other 25}, classified by the
validated research niche patterns (esports before sports so 'LoL: A vs B'
doesn't fall through on ' vs '). cfg fak_retry_niche_s overrides per key;
fak_retry_s stays the fallback (tennis: no measurement yet) and 0 still
disables the feature. Paper-parity: same map both bots. test t8 covers the
map, first-match classing, fallback, and config override.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

config.live.example.json

@@ -5,6 +5,8 @@
   "bankroll_pct": 0.04,
   "price_guard_abs": 0.05,
   "fak_retry_s": 10,
+  "fak_retry_niche_s": {"crypto": 4, "esports": 10, "sports": 25,
+                        "geo": 25, "politics": 25, "other": 25},
   "taker_fee_rate": 0.03,
   "discord_webhook": "",
   "follow": {