Credibility pass: the illusion tests roll both ways, and the seams from the last batch are sanded

Scope: 66b5c06..HEAD.

- The rev-27 illusion tests search seeds for a believed and a doubted
  roll and assert fixed life totals; seed 42 alone never believed, so
  the BLUNT pricing went unchecked.
- Three docblocks stranded above newly inserted functions are back on
  their own (openCreatureStack, resolvedBlow, castTrace).
- POWER ATTACK's life trade is one helper instead of three copies; the
  goat's charge distance is one helper for its validator, its ram and
  its pricing.
- The family list loads once into a shared store; the lobby and gallery
  share one talk filter; Board uses the engine's neighbor().
- A creature's blow shows the card that summoned it by the creature's
  kind, not by matching the blow's display name.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jm2auWk6RP71CjaAb4FMoG

packages/engine/test/creatures.test.ts

@@ -931,8 +931,8 @@ describe("the imp's fire is a spell (rev 8)", () => {
     if (!r.ok) throw new Error(r.error);
     state = r.state;
     if (!state.stack) state = must(state, "imp-owner", { type: "endTurn", draw: 0 });
-    // The scorch rides the stack now: a counteraction window, spell-kind,
-    // named for the imp so the counter is played against the scorch, never a punch.
+    // The scorch rides the stack as a spell-kind counteraction window,
+    // named for the imp: the counter is played against the scorch.
     expect(state.stack?.creatureId).toBeTruthy();
     expect(state.stack?.kind).toBe("spell");
     expect(state.stack?.sourceName).toBe("fire imp's scorch");