design: add brand tokens, apply to homepage v1, extend T-606

- docs/brand.md 品牌单一真相源（靛蓝=生成/琥珀=点数、字体/术语/语气 + 可复制 CSS 变量）
- v1 原型精修：色彩语言按 brand rule 归位（点数统一琥珀、生成图标统一靛蓝）、生成台连接与导航配平
- 06-tasks.md T-606 验收加「首页 + portal 同套 brand token」；README 导航登记 brand.md

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

prototypes/cmhub-homepage-v1.svg

@@ -56,9 +56,9 @@
     <rect x="144" y="37" width="4" height="17" rx="2" fill="#E8A02D"/>
     <text x="164" y="52" font-size="22" font-weight="700" class="ink">cmhub</text>
 
-    <text x="470" y="51" font-size="15.5" font-weight="500" class="soft">功能</text>
-    <text x="560" y="51" font-size="15.5" font-weight="500" class="soft">计费</text>
-    <text x="650" y="51" font-size="15.5" font-weight="500" class="soft">文档</text>
+    <text x="812" y="51" font-size="15.5" font-weight="500" class="soft">功能</text>
+    <text x="902" y="51" font-size="15.5" font-weight="500" class="soft">计费</text>
+    <text x="992" y="51" font-size="15.5" font-weight="500" class="soft">文档</text>
 
     <text x="1085" y="51" font-size="15.5" font-weight="600" class="ink">登录</text>
     <rect x="1160" y="26" width="160" height="40" rx="10" fill="url(#btn)"/>
@@ -73,7 +73,7 @@
     <text x="118" y="252" class="h1">把商品图和一句话，</text>
     <text x="118" y="322" class="h1">变成能卖货的</text>
     <text x="500" y="322" class="h1" fill="#5B4BEF">标题与主图</text>
-    <text x="810" y="322" class="h1">。</text>
+    <text x="786" y="322" class="h1">。</text>
 
     <text x="120" y="392" class="lead">cmhub 把「生成标题」「生成主图」封装成 HTTP 接口，桌面端拿</text>
     <text x="120" y="422" class="lead">API Key 直接用，按点数计费——换底层模型，价格不变。</text>
@@ -114,11 +114,13 @@
     <text x="868" y="290" font-size="15" font-weight="600" class="ink">白色纯棉基础款 T 恤</text>
     <text x="868" y="313" font-size="13" class="faint">提示词：夏季清爽 · 男女同款 · 主图去背景</text>
 
-    <!-- pipeline: thread + 点数计量 -->
-    <line x1="1041" y1="344" x2="1041" y2="378" stroke="url(#thread)" stroke-width="2.5" stroke-dasharray="3 4"/>
-    <rect x="946" y="348" width="190" height="26" rx="13" fill="#FBEFD9"/>
-    <path d="M962 361 h10 M967 356 v10" stroke="#C9821A" stroke-width="2" stroke-linecap="round"/>
-    <text x="982" y="365" class="metric" fill="#9A6510">生成中 · 计量扣点</text>
+    <!-- pipeline: 生成 + 点数计量（输入 ↓ 计量 ↓ 输出） -->
+    <line x1="1041" y1="338" x2="1041" y2="348" stroke="url(#thread)" stroke-width="2.5"/>
+    <rect x="928" y="348" width="226" height="28" rx="14" fill="#FBEFD9"/>
+    <circle cx="950" cy="362" r="6" fill="none" stroke="#C9821A" stroke-width="2"/>
+    <path d="M950 358 v4 l3 2" stroke="#C9821A" stroke-width="1.7" fill="none" stroke-linecap="round" stroke-linejoin="round"/>
+    <text x="968" y="367" class="metric" fill="#9A6510">生成中 · 按点数计量</text>
+    <path d="M1034 382 l7 7 l7 -7" stroke="#D6B678" stroke-width="2.2" fill="none" stroke-linecap="round" stroke-linejoin="round"/>
 
     <!-- OUTPUT -->
     <text x="790" y="410" class="kicker">输出</text>
@@ -126,15 +128,15 @@
     <g>
       <rect x="790" y="422" width="330" height="34" rx="9" fill="#F3F2FF"/>
       <text x="806" y="444" class="chiptxt">纯棉白T恤男夏季薄款情侣装宽松半袖</text>
-      <text x="1104" y="444" text-anchor="end" class="metric" fill="#5B4BEF">−2</text>
+      <text x="1104" y="444" text-anchor="end" class="metric" fill="#C9821A">−2</text>
 
       <rect x="790" y="464" width="330" height="34" rx="9" fill="#F3F2FF"/>
       <text x="806" y="486" class="chiptxt">日系基础款白色短袖打底衫百搭上衣</text>
-      <text x="1104" y="486" text-anchor="end" class="metric" fill="#5B4BEF">−2</text>
+      <text x="1104" y="486" text-anchor="end" class="metric" fill="#C9821A">−2</text>
 
       <rect x="790" y="506" width="330" height="34" rx="9" fill="#F3F2FF"/>
       <text x="806" y="528" class="chiptxt">纯色圆领纯棉T恤男女同款舒适透气</text>
-      <text x="1104" y="528" text-anchor="end" class="metric" fill="#5B4BEF">−2</text>
+      <text x="1104" y="528" text-anchor="end" class="metric" fill="#C9821A">−2</text>
     </g>
     <!-- generated 主图 -->
     <rect x="1138" y="422" width="154" height="118" rx="14" fill="url(#thumbOut)" stroke="#E7E3FA"/>
@@ -197,18 +199,18 @@
     <rect x="152" y="1342" width="52" height="52" rx="14" fill="#ECEBFF"/>
     <path d="M167 1362 h22 M167 1370 h22 M167 1378 h14" stroke="#5B4BEF" stroke-width="2.4" stroke-linecap="round"/>
     <text x="152" y="1432" class="cardtitle">生成标题</text>
-    <rect x="560" y="1352" width="104" height="30" rx="15" fill="#F3F2FF"/>
-    <text x="612" y="1372" text-anchor="middle" class="metric" fill="#5B4BEF">2 点 / 次起</text>
+    <rect x="560" y="1352" width="104" height="30" rx="15" fill="#FBEFD9"/>
+    <text x="612" y="1372" text-anchor="middle" class="metric" fill="#C9821A">2 点 / 次起</text>
     <text x="152" y="1468" class="body">给商品生成多个吸睛中文标题，可纯文字，也可看图生成。</text>
     <text x="152" y="1494" class="body">别名调用，换底层模型价格不变；失败自动退点。</text>
   </g>
   <!-- card B: 主图 -->
   <g filter="url(#softsm)"><rect x="744" y="1310" width="576" height="230" rx="18" fill="#fff"/></g>
   <g>
-    <rect x="776" y="1342" width="52" height="52" rx="14" fill="#FBEFD9"/>
-    <rect x="789" y="1356" width="26" height="24" rx="5" fill="none" stroke="#C9821A" stroke-width="2.2"/>
-    <circle cx="797" cy="1364" r="2.6" fill="#C9821A"/>
-    <path d="M791 1378 l6 -7 l5 5 l4 -5 l6 7 z" fill="#C9821A"/>
+    <rect x="776" y="1342" width="52" height="52" rx="14" fill="#ECEBFF"/>
+    <rect x="789" y="1356" width="26" height="24" rx="5" fill="none" stroke="#5B4BEF" stroke-width="2.2"/>
+    <circle cx="797" cy="1364" r="2.6" fill="#5B4BEF"/>
+    <path d="M791 1378 l6 -7 l5 5 l4 -5 l6 7 z" fill="#5B4BEF"/>
     <text x="776" y="1432" class="cardtitle">生成主图 / 改图</text>
     <rect x="1176" y="1352" width="112" height="30" rx="15" fill="#FBEFD9"/>
     <text x="1232" y="1372" text-anchor="middle" class="metric" fill="#C9821A">10 点 / 次起</text>