竞赛演示模式：首屏降噪与预置导览

- demo_mode 配置项（默认开）：不弹初始设置，LLM/语义警告横幅降级为顶栏状态点
- 顶栏新增'开始演示'导览（驾驶舱→新岗位发现→Java演化→匹配诊断四步预置路线）
- 图谱默认降噪：场景/行业图层默认关、关系标签默认关（悬停/缩放显示）
- 演化页默认锁定 Java 强样例；数据版本徽标标注'（模拟）'；联系方式移入设置页
- start.bat/start.sh 启动脚本

webui/graph.js

@@ -10,8 +10,8 @@
   const G = {
     nodes: [], edges: [], events: [], idx: {},
     cam: { x: 0, y: 0, k: 1 },          // 相机：世界 -> 屏幕  screen = (world - cam.pan) * k ... 使用 cam.x/y 为平移（屏幕像素）
-    showLabels: true,
-    filters: { types: { Job: true, Skill: true, Industry: true, Scenario: true }, category: "", level: "",
+    showLabels: false,                     // 默认关闭：悬停/选中/缩放时才显示
+    filters: { types: { Job: true, Skill: true, Industry: false, Scenario: false }, category: "", level: "",
                edges: { required: true, preferred: true, applies: true, belongs: true } },
     selected: null,                      // 选中节点 id
     soloJob: null,                       // 岗位子图模式：只看该岗位及其一跳邻居
@@ -444,7 +444,7 @@
     $("#fp-category").onchange = (e) => { G.filters.category = e.target.value; requestDraw(); drawMinimap(); };
     $("#fp-level").onchange = (e) => { G.filters.level = e.target.value; requestDraw(); drawMinimap(); };
     $("#fp-reset").onclick = () => {
-      G.filters = { types: { Job: true, Skill: true, Industry: true, Scenario: true }, category: "", level: "",
+      G.filters = { types: { Job: true, Skill: true, Industry: false, Scenario: false }, category: "", level: "",
                     edges: { required: true, preferred: true, applies: true, belongs: true } };
       $$("#graph-filter-panel input[data-ftype]").forEach((cb) => { cb.checked = true; });
       $$("#graph-filter-panel input[data-etype]").forEach((cb) => { cb.checked = true; });
@@ -487,7 +487,7 @@
       if (!v) return false;
       G.cam = v.cam;
       G.filters = Object.assign(
-        { types: { Job: true, Skill: true, Industry: true, Scenario: true }, category: "", level: "",
+        { types: { Job: true, Skill: true, Industry: false, Scenario: false }, category: "", level: "",
           edges: { required: true, preferred: true, applies: true, belongs: true } },
         v.filters);
       G.filters.edges = Object.assign({ required: true, preferred: true, applies: true, belongs: true },