docs(design): v0.2 弹珠小游戏与蹲下系统设计准备

- 弹珠小游戏执行案 v0.2.1（经6维度对抗性审查修订25项问题）
- 蹲下系统执行案 v0.2.0（玩家控制器姿态扩展）
- v0.2 范围定义（对标 v01-范围）
- 弹珠操作手感与系统决策头脑风暴共识
- 弹珠配置表（属性/场地/NPC/参数，4个文件）
- 更新设计文档索引与 GameConfig 说明

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

GameConfig/marble-config.json

@@ -0,0 +1,41 @@
+{
+  "_meta": {
+    "doc": "弹珠小游戏配置（v0.2）",
+    "source": "弹珠小游戏-执行案.md v0.2.1",
+    "field_note": "value=建议值（程序导入用），min/max=可调范围（调参参考），unit=单位，note=说明"
+  },
+  "circleRule": {
+    "circleRadius_m": { "value": 1.0, "min": 0.8, "max": 1.5, "unit": "m", "note": "弹出判定圈半径" },
+    "targetCount": { "value": 5, "min": 3, "max": 8, "unit": "颗", "note": "圈中央目标弹珠数" },
+    "popTolerance_m": { "value": 0.01, "min": 0.005, "max": 0.02, "unit": "m", "note": "弹出判定容差，统一带容差阈值" },
+    "boundaryExpand_m": { "value": 0.5, "min": 0.3, "max": 1.0, "unit": "m", "note": "场地隐形反弹边界外扩" },
+    "betMarbleCount": { "value": 1, "min": 1, "max": 3, "unit": "颗", "note": "胜负流转的对赌弹珠数" },
+    "turnOrder": { "value": "player_first", "note": "v0.2 固定玩家先手" }
+  },
+  "operation": {
+    "maxDragScreenRatio": { "value": 0.15, "min": 0.08, "max": 0.25, "unit": "屏幕高度占比", "note": "力度100%对应的拖拽距离，相对屏幕高度" },
+    "minValidPower": { "value": 0.10, "min": 0.05, "max": 0.20, "unit": "比例", "note": "低于此松开视为取消" },
+    "predictionLineLength_m": { "value": 3.0, "min": 2.0, "max": 5.0, "unit": "m", "note": "轨迹预测线最大显示长度" },
+    "maxLaunchSpeed_mps": { "value": 8.0, "min": 5.0, "max": 12.0, "unit": "m/s", "note": "100%力度弹射初速度，对所有弹珠相同" },
+    "shooterHighlightFreq_hz": { "value": 1.0, "min": 0.5, "max": 2.0, "unit": "Hz", "note": "PlayerAim 射手弹珠脉冲发光频率" }
+  },
+  "physics": {
+    "stopSpeedThreshold_mps": { "value": 0.05, "min": 0.02, "max": 0.10, "unit": "m/s", "note": "判定弹珠停止的速度阈值" },
+    "stableTime_s": { "value": 1.0, "min": 0.5, "max": 2.0, "unit": "秒", "note": "低于阈值持续至此判定停止" },
+    "simulateTimeout_s": { "value": 15, "min": 10, "max": 30, "unit": "秒", "note": "物理结算超时强制停止" },
+    "boundaryRestitution": { "value": 0.5, "min": 0.3, "max": 0.7, "unit": "系数", "note": "弹珠-场地边界反弹系数" },
+    "frictionCombineRule": { "value": "venue_friction + marble_frictionAdd", "note": "最终摩擦=场地摩擦+弹珠摩擦加成" }
+  },
+  "inventory": {
+    "initialCount": { "value": 5, "min": 3, "max": 10, "unit": "颗", "note": "玩家初始对战库存" },
+    "guaranteeFloor": { "value": 3, "min": 2, "max": 5, "unit": "颗", "note": "保底下限，玩家败时库存不低于此" }
+  },
+  "timing": {
+    "readyDuration_s": { "value": 0.8, "min": 0.5, "max": 1.2, "unit": "秒", "note": "进入就位表现（原位转向+蹲下）" },
+    "enterCameraDuration_s": { "value": 0.6, "min": 0.4, "max": 1.0, "unit": "秒", "note": "第三人称→斜俯视相机切换" },
+    "exitCameraDuration_s": { "value": 0.6, "min": 0.4, "max": 1.0, "unit": "秒", "note": "斜俯视→第三人称相机切换" },
+    "standupDuration_s": { "value": 0.8, "min": 0.5, "max": 1.2, "unit": "秒", "note": "退出站起表现" },
+    "resultDisplayDuration_s": { "value": 2.0, "min": 1.5, "max": 3.0, "unit": "秒", "note": "胜负结果显示时长" },
+    "npcThinkDelay_s": { "value": 1.0, "min": 0.5, "max": 2.0, "unit": "秒", "note": "NPC 思考延迟" }
+  }
+}