Add anti-synergy warnings: CLASHES pairs and per-joker CAUTIONS

Warning-only data in synergies.lua — never touches the synergy score.
Tooltips gain a red 'Clashes - <owned joker>: <why>' line when a hovered
joker fights one you own (Ride the Bus + Pareidolia, Vampire vs Steel
Joker/Lucky Cat, Smeared vs Flower Pot), and a 'Caution:' line in the
buy area for jokers that harm a board you keep (Ceremonial Dagger,
Madness, Stencil). Learning mode keeps warnings — they teach.

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

CLAUDE.md

@@ -136,6 +136,10 @@ Three-layer split; `JCA` is the single global namespace:
 - Unknown joker keys (from other mods) must keep scoring 0 — never index
   `JCA.db[key]` without a nil guard.
 - Display names go through `localize{type='name_text', set='Joker', ...}` with a
-  pcall + `center.name` fallback; anti-synergies are deliberately not modeled.
+  pcall + `center.name` fallback.
+- Anti-synergies never affect scores. Known traps are warning-only data:
+  `CLASHES` (pairwise, red "Clashes -" tooltip line vs owned jokers) and
+  `CAUTIONS` (per-joker, buy-area "Caution:" line) in `synergies.lua`, same
+  ~34-char blurb budget as `PAIRS`. Learning mode keeps warnings visible.
 - The UI hooks are the only untested-in-game surface; if a tooltip regression is
   reported, suspect the `aut.info` entry format first and check the lovely log.