feat: 新增物理弹球实验室及配套功能

1. 新增物理弹球游戏全套代码，包含物理引擎、规则、渲染、游戏逻辑、存档、音效、UI
2. 新增物理弹球相关调试与单元测试脚本
3. 优化私有剪贴上传功能：增加200MB上传限制与错误提示
4. 修复复古弹球桌的光滑面防粘附与休眠逻辑

dev_test_scripts/debug/debug_physics_balls_stuck_escape.js

@@ -0,0 +1,127 @@
+/* ============================================================
+ * debug_physics_balls_stuck_escape.js · 物理弹球 · 卡球逃脱验证
+ * 规则：球陷缝隙 0.5s 后横向滑出缺口继续下落；禁止向上弹射
+ * （"必须落下后才能上去"，唯一上升途径是底部输送带）。
+ * 验证：1) 卡球能逃脱并下落/回收  2) 上升幅度 <=120px  3) 左右方向有随机性
+ * 运行：node dev_test_scripts/debug/debug_physics_balls_stuck_escape.js
+ * ============================================================ */
+'use strict';
+const fs = require('fs');
+const path = require('path');
+const vm = require('vm');
+
+const LAB = path.join(__dirname, '..', '..', 'public', 'tools', 'thought_lab', 'labs', 'physics_balls');
+const ctx = {
+  Math,
+  console,
+  PBAudio: { fire() {}, hit() {}, wall() {}, item() {}, breakBlock() {}, over() {} },
+  PBStorage: { getEscape() { return 50; } }
+};
+vm.createContext(ctx);
+for (const f of ['pb_physics.js', 'pb_rules.js', 'pb_game.js']) {
+  vm.runInContext(fs.readFileSync(path.join(LAB, f), 'utf8'), ctx, { filename: f });
+}
+
+const P = ctx.PBPhysics, G = ctx.PBGame;
+
+// 跑 8s：成功 = 被回收 或 下落到 startY+200 以下；同时记录最小 y（上升幅度）
+function runScenario(setup, startY) {
+  const g = G.create();
+  g.state = 'fly';
+  setup(g);
+  let minY = 1e9, maxX = 0, minX = 1e9, outcome = 'stuck';
+  for (let i = 0; i < 60 * 8; i++) {
+    G.update(g, 1 / 60);
+    if (!g.balls.length) { outcome = 'recycled'; break; }
+    const b = g.balls[0];
+    minY = Math.min(minY, b.y);
+    maxX = Math.max(maxX, b.x);
+    minX = Math.min(minX, b.x);
+    if (b.y > startY + 200) { outcome = 'fell'; break; }
+  }
+  return { outcome, minY, spread: maxX - minX, g };
+}
+
+let ok = true;
+function check(name, res, startY) {
+  const escaped = res.outcome !== 'stuck';
+  const noLaunch = res.minY > startY - 120;   // 不允许向上弹射超过 120px
+  const pass = escaped && noLaunch;
+  console.log((pass ? 'PASS ' : 'FAIL ') + name +
+    ' outcome=' + res.outcome + ' minY=' + (res.minY === 1e9 ? 'recycled' : res.minY.toFixed(1)) +
+    ' hSpread=' + res.spread.toFixed(0));
+  ok = pass && ok;
+}
+
+// rest 默认 0.2：隔离"逃脱冲量本身"，排除高弹块自然反弹的干扰
+const mkCircle = (g, x, y, r, rest) => {
+  const b = P.makeCircle({ shape: 'circle', x, y, r, isStatic: true, friction: 0.35, restitution: rest === undefined ? 0.2 : rest, tag: 'block' });
+  b.data = { hp: 99, shape: 'circle', r };
+  g.blocks.push(b);
+};
+const mkBall = (g, x, y) => {
+  const ball = P.makeCircle({ shape: 'circle', x, y, r: 7, friction: 0.08, restitution: 0.95, tag: 'ball' });
+  ball.data = { big: false };
+  g.balls.push(ball);
+};
+
+// 场景1：球静止放在两圆块谷地 → 应横向滑出后下落，不上天
+check('谷地卡球逃脱', runScenario((g) => {
+  mkCircle(g, 180, 400, 22); mkCircle(g, 224, 400, 22);
+  mkBall(g, 202, 381);
+}, 381), 381);
+
+// 场景2：球静止放在单块顶部 → 应被推离块顶后下落；且单接触不触发研磨（块 HP 不变）
+{
+  const res = runScenario((g) => {
+    mkCircle(g, 200, 400, 22);
+    mkBall(g, 200, 371);
+  }, 371);
+  check('块顶停球逃脱', res, 371);
+  const intact = res.g.blocks.length === 1 && res.g.blocks[0].data.hp === 99;
+  console.log((intact ? 'PASS ' : 'FAIL ') + '单接触不研磨 hp=' + (res.g.blocks[0] ? res.g.blocks[0].data.hp : 'gone'));
+  ok = intact && ok;
+}
+
+// 场景5：球楔入两低血块夹角 → 研磨快速打碎砖块、留出空间后下落
+{
+  const res = runScenario((g) => {
+    mkCircle(g, 180, 400, 22); mkCircle(g, 224, 400, 22);
+    g.blocks.forEach(b => { b.data.hp = 8; });
+    mkBall(g, 202, 381);
+  }, 381);
+  const ground = res.g.blocks.length === 0;
+  const pass = ground && res.outcome !== 'stuck';
+  console.log((pass ? 'PASS ' : 'FAIL ') + '夹角研磨开空间 outcome=' + res.outcome + ' blocksLeft=' + res.g.blocks.length);
+  ok = pass && ok;
+}
+
+// 场景3：球停底部弧面（无砖块接触）→ 1.2s 后应被回收
+check('底部停球回收', runScenario((g) => {
+  mkBall(g, 210, 790);
+}, 790), 790);
+
+// 场景4：单接触停球逃脱，横向方向应有随机性（左右都出现）
+{
+  const dirs = [];
+  for (let k = 0; k < 10; k++) {
+    const g = G.create();
+    g.state = 'fly';
+    mkCircle(g, 200, 400, 22);
+    mkBall(g, 200 + (Math.random() * 4 - 2), 371);   // 真实落点总有微小偏移
+    let firstVx = null;
+    for (let i = 0; i < 60 * 3; i++) {
+      G.update(g, 1 / 60);
+      if (!g.balls.length) break;
+      const b = g.balls[0];
+      if (firstVx === null && Math.abs(b.vx) > 200) { firstVx = b.vx; break; }
+    }
+    if (firstVx !== null) dirs.push(firstVx > 0 ? 'R' : 'L');
+  }
+  const hasL = dirs.includes('L'), hasR = dirs.includes('R');
+  const pass = dirs.length >= 6 && hasL && hasR;
+  console.log((pass ? 'PASS ' : 'FAIL ') + '逃逸方向随机性 ' + dirs.join(''));
+  ok = pass && ok;
+}
+
+process.exit(ok ? 0 : 1);