Cap generic mult/xmult bonus per candidate; opt Stencil out of it

Any xMult joker used to pulse 'recommended' on a board of four unrelated
+Mult/+Chips jokers: the generic engine-complement +1 in JCA.score
accumulated once per owned joker in partners_for, reaching the threshold
of 4 with zero listable partners (pairwise scores never hit 2), so the
card pulsed while its own tooltip said 'No synergy with your jokers.'

- partners_for now counts the generic +1 once per candidate. Tag/pair
  scores are even, so the generic bonus can no longer flip a
  recommendation at all; a pulsing card always has a nameable partner.
- Joker Stencil is the one xMult joker the generic rule actively
  misreads (its multiplier grows with EMPTY slots), so entries support
  {no_generic = true} which suppresses the rule in score() and the
  generic fallback lines in explain(). Stencil also gains copy_target:
  its real famous synergy is being copied by Blueprint/Brainstorm.

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

CLAUDE.md

@@ -62,8 +62,15 @@ Three-layer split; `JCA` is the single global namespace:
 - `main.lua` — engine + game integration:
   - Scoring: `JCA.score(a, b)` = explicit pair bonus (+4) + 2 per give→want tag
     match in each direction + 1 for the generic "+Mult/+Chips source with an
-    ×Mult joker" complement. `JCA.partners_for(card)` aggregates over
-    `G.jokers.cards`; total ≥ `JCA.config.threshold` ⇒ recommended.
+    ×Mult joker" complement (second return value flags when that +1 applied).
+    `JCA.partners_for(card)` aggregates over `G.jokers.cards`; total ≥
+    `JCA.config.threshold` ⇒ recommended. The generic +1 counts toward the
+    total once per candidate, not per owned joker — since tag/pair scores are
+    even and the threshold is 4, the generic bonus alone can never trigger a
+    recommendation, so a pulsing card always has a nameable partner. Jokers
+    whose multiplier the generic rule misreads opt out with
+    `{no_generic = true}` in `synergies.lua` (Joker Stencil: its ×Mult grows
+    with *empty* slots, so "+Mult jokers feed it" is backwards).
   - UI hooks: wraps `Card:generate_UIBox_ability_table` to append a tooltip entry
     to `aut.info` (format: array of rows-of-UIT-nodes plus a `.name` string —
     must match what vanilla `info_tip_from_rows` expects), and wraps