feat(tavern): a real cat (Pet Cats Pack, CC-0)

The old 'cat' used a char-goblin sprite (green monster). Replaced with actual
pixel cats from the Pet Cats Pack (CC-0, commercial-ok):
- html/assets/cats/cat1..6-idle.png — 6 cats, 10-frame 50x50 idle strips.
- catSprites.js: loads + animates a cat sprite (RK.drawCatCanvas), flips to face left.
- tileRenderer: draws entities with kind 'cat' via the cat sprite path (shadow + frame).
- tavernLife: spawns a RANDOM cat that wanders the customer floor (not behind the
  bar), injected as kind 'cat' with its catSprite id. Degrades to a villager if
  catSprites.js isn't loaded.
- tavern.html loads catSprites.js.

Client-only (no server change). Suite 57 suites / 413 tests green.

html/js/render/catSprites.js

@@ -0,0 +1,44 @@
+(function (root) {
+    'use strict';
+    var RK = root.RK = root.RK || {};
+
+    // Pet Cats Pack (CC-0). Each idle strip is 10 frames of 50x50 laid out horizontally.
+    var FRAMES = 10, FW = 50, FH = 50, FRAME_MS = 150;
+    var CATS = ['cat1', 'cat2', 'cat3', 'cat4', 'cat5', 'cat6'];
+    var images = {};
+
+    function imgFor(id) {
+        if (!CATS.includes(id)) id = 'cat3';
+        if (!images[id]) {
+            var im = new Image();
+            im.src = 'assets/cats/' + id + '-idle.png';
+            images[id] = im;
+        }
+        return images[id];
+    }
+
+    RK.catIds = function () { return CATS.slice(); };
+    RK.randomCatId = function () { return CATS[Math.floor(Math.random() * CATS.length)]; };
+    RK.isCat = function (id) { return CATS.indexOf(id) !== -1; };
+
+    // Draw an animated cat centered in its cell, feet near the bottom of the tile. Flips to face left.
+    RK.drawCatCanvas = function (ctx, e, cell, now) {
+        var im = imgFor(e.catSprite || 'cat3');
+        if (!im.complete || !im.naturalWidth) return false;
+        var frame = Math.floor((now || 0) / FRAME_MS) % FRAMES;
+        var sx = frame * FW;
+        var size = cell * 1.25;                       // a touch bigger than a tile
+        var dx = e.x * cell + (cell - size) / 2;
+        var dy = e.y * cell + cell - size + cell * 0.12;
+        ctx.save();
+        ctx.imageSmoothingEnabled = false;
+        if (e.facing === 'left') {
+            ctx.translate(dx + size, dy); ctx.scale(-1, 1);
+            ctx.drawImage(im, sx, 0, FW, FH, 0, 0, size, size);
+        } else {
+            ctx.drawImage(im, sx, 0, FW, FH, dx, dy, size, size);
+        }
+        ctx.restore();
+        return true;
+    };
+})(window);

html/js/render/tavernLife.js

@@ -78,7 +78,8 @@
         return { minY: 3, maxY: rows - 2, minX: 1, maxX: cols - 2 };
     }
     function catArea(cols, rows) {
-        return { minY: 1, maxY: rows - 1, minX: 1, maxX: cols - 2 };
+        // The customer floor (in front of the bar) — not behind the counter, not the walls.
+        return { minY: 4, maxY: rows - 2, minX: 1, maxX: cols - 2 };
     }
 
     // ---- Speech bubbles ---------------------------------------------------------
@@ -220,8 +221,13 @@
                 }));
         }
 
-        // (No "cat": it used the char-goblin sprite, which read as a green monster stuck in the
-        // wall. Left out until there's an actual pet/critter sprite.)
+        // A tavern cat — a random pixel cat from the Pet Cats Pack that wanders the floor.
+        var catSpot = findFloor(4, rows - 4);
+        var cat = makeNPC('cat', 'cat', null, catSpot.x, catSpot.y, {
+            label: null, color: '#e8a060', role: 'cat', roamArea: catArea(cols, rows)
+        });
+        cat.catSprite = (RK.randomCatId ? RK.randomCatId() : 'cat3');
+        this.npcs.push(cat);
     };
 
     TavernLife.prototype._pickTarget = function (npc, scene) {
@@ -303,9 +309,10 @@
                 scene.entities.push({
                     id: npc.id,
                     x: npc.x, y: npc.y,
-                    kind: 'avatar',
+                    kind: npc.role === 'cat' ? 'cat' : 'avatar',
                     avatar: npc.avatar,
                     appearance: npc.appearance,
+                    catSprite: npc.catSprite || null,
                     color: npc.color,
                     char: npc.role === 'cat' ? 'c' : '@',
                     facing: npc.facing,

html/js/render/tileRenderer.js

@@ -188,6 +188,11 @@
                 ctx.stroke();
                 continue;
             }
+            // Tavern cat — a standalone animated sprite (Pet Cats Pack), not a char-atlas avatar.
+            if (e.kind === 'cat') {
+                drawEntityShadow(ctx, e.x * cell + cell / 2, e.y * cell + cell * 0.9, cell * 0.28, cell * 0.11);
+                if (window.RK && RK.drawCatCanvas && RK.drawCatCanvas(ctx, e, cell, now)) continue;
+            }
             // Character-like entity: soft ground shadow, then the sprite (or fallback circle).
             drawEntityShadow(ctx, e.x * cell + cell / 2, e.y * cell + cell * 0.92, cell * 0.34, cell * 0.14);
             // Roguelike character sprite, or premium animated skin; else the fallback circle.

html/tavern.html

@@ -13,6 +13,7 @@
     <script src="js/render/charCustomize.js"></script>
     <script src="js/render/atlas.js"></script>
     <script src="js/render/charSprites.js"></script>
+    <script src="js/render/catSprites.js"></script>
     <script src="js/render/assetPacks.js"></script>
     <script src="js/render/avatarVisuals.js"></script>
     <script src="js/render/designedRoom.js"></script>