Make Bone Knit a chance-based room heal

The perk now grants a 3% roll per stack to mend half a heart on combat
room clears instead of a guaranteed heal. Worm Gut's guaranteed room
heal is unchanged; the new roomHealChance stat is separate.

js/perks.js

@@ -20,7 +20,7 @@ const PERKS = [
   { id: 'thickhide',name: 'Thick Hide',      desc: '+4% chance to ignore damage', apply: s => { s.armor += 1 / 24; } },
   { id: 'secondwind',name: 'Second Wind',    desc: '+0.15s hurt immunity',  apply: s => { s.invBonus += 0.15; } },
   { id: 'scrapfeed',name: 'Scrap Feed',      desc: '5% less ammo consumed', apply: s => { s.ammoEff *= 1.05; } },
-  { id: 'boneknit', name: 'Bone Knit',       desc: 'Heal ½ heart after each combat room', apply: s => { s.roomHeal += 1; } },
+  { id: 'boneknit', name: 'Bone Knit',       desc: '3% chance to heal ½ heart after combat rooms', apply: s => { s.roomHealChance += 0.03; } },
   { id: 'spiteflesh',name: 'Spite Flesh',    desc: 'Contact attackers take damage', apply: s => { s.thorns += 4; } },
   { id: 'carrion',  name: 'Carrion Sense',   desc: '+8% pickup radius and pull speed', apply: s => { s.magnet *= 1.08; s.magnetPull *= 1.08; } },
   { id: 'sinew',    name: 'Sinew Weave',     desc: '+3% move speed and range', apply: s => { s.speedMul *= 1.03; s.rangeMul *= 1.03; } },

js/player.js

@@ -19,7 +19,7 @@ function initPlayer() {
       armor: 0, luck: 0, magnet: 1, magnetPull: 1, xpMul: 1, crit: 0.05, critMul: 2, bloodlust: 0,
       bleed: 0, igniteChance: 0, slowOnHit: 0, stunOnHit: 0, acidOnHit: 0, pullOnHit: 0,
       chain: 0, knockbackMul: 1, invBonus: 0, ammoEff: 1, ammoPickupMul: 1,
-      roomHeal: 0, thorns: 0, retaliate: 0, sizeMul: 1, mortar: 0, frenzy: 0,
+      roomHeal: 0, roomHealChance: 0, thorns: 0, retaliate: 0, sizeMul: 1, mortar: 0, frenzy: 0,
       orbSpeedMul: 1, orbDmgMul: 1, overShield: 0,
       rerolls: 0, rerollPerLevel: 0,
       maxHp: 6,

js/rooms.js

@@ -180,6 +180,13 @@ function recordRoomClear(room) {
     healPlayer(G.player.stats.roomHeal);
     if (G.player.hp > before) spawnText(G.player.x, G.player.y - 18, 'ROOM KNIT +' + (G.player.hp - before), '#d98991');
   }
+  // Bone Knit perk: small chance of a half-heart mend on each combat clear
+  if (room.type === 'combat' && G.player.stats.roomHealChance > 0 && G.player.hp < G.player.stats.maxHp &&
+      chance(Math.min(0.9, G.player.stats.roomHealChance))) {
+    const before = G.player.hp;
+    healPlayer(1);
+    if (G.player.hp > before) spawnText(G.player.x, G.player.y - 30, 'BONE KNIT +' + (G.player.hp - before), '#d98991');
+  }
 }
 
 function nextFloor() {