Phase 3: 12 hook passives with conditional damage, auras, and kill/room effects

- dmgLiveMul live damage channel wired into fireWeapon, sawTick, fireBeam, orbitals
- Dead Weight (execute), Cauterized Veins (burn bonus), Pain Engine, Iron Lung,
  Slaughter Rhythm, Hollow Choir, Sawbone Coil, Glutton's Gut, Thresher Plate,
  Blood Moat, Meat Hook, Blood Debt
- Iron Lung re-armed per room in enterRoom; Slaughter Rhythm stamps kills
- Targeted smoke tests for the five stat-conditional effects; icons + docs

js/rooms.js

@@ -67,6 +67,8 @@ function enterRoom(gx, gy) {
 
   // spawn protection: brief invincibility walking into a fresh room
   if (G.player) G.player.invT = Math.max(G.player.invT, 1.0);
+  // Iron Lung: re-arm the once-per-room hit block
+  if (G.player && G.player.stats.ironLung > 0) G.player.ironLungReady = true;
 
   if (!room.visited) {
     room.visited = true;