chore: seal Design Vision v1 and monorepo scaffold

Archive the differentiated YuXinGu product docs, AI engineering system,
design contract, and Go/Vue scaffold. Next execution prioritizes Cece-parity
over early innovation (see .ai/product/STRATEGY.md).

Co-authored-by: Cursor <cursoragent@cursor.com>

css/hub.css

@@ -0,0 +1,26 @@
+/* 一级聚合页：认识自己 / 私域活动 / 我的 */
+.hub-list{display:flex;flex-direction:column;gap:10px;padding:0 16px 20px}
+.hub-item{
+  display:flex;align-items:center;gap:14px;padding:16px;
+  background:#fff;border-radius:14px;text-decoration:none;color:var(--text);
+  box-shadow:0 2px 10px rgba(0,0,0,0.04);transition:transform .12s;
+}
+.hub-item:active{transform:scale(0.98)}
+.hub-item .hi{
+  width:48px;height:48px;border-radius:12px;
+  display:flex;align-items:center;justify-content:center;
+  font-size:22px;flex-shrink:0;
+}
+.hub-item .ht{font-size:16px;font-weight:600}
+.hub-item .hd{font-size:12px;color:var(--sub);margin-top:3px}
+.hub-item .ha{margin-left:auto;color:#ccc;font-size:18px}
+.hi-gold{background:#FFF8E6;color:#C8923A}
+.hi-blue{background:#E6F0FF;color:#4A90E2}
+.hi-purple{background:#F0E6FF;color:#8B5CF6}
+.hi-green{background:#E6FFE8;color:#5CB85C}
+.hi-rose{background:#FFECEC;color:#E54D42}
+.hub-empty{
+  margin:24px 16px;padding:28px 20px;text-align:center;
+  background:#fff;border-radius:16px;color:var(--sub);font-size:14px;line-height:1.7;
+  box-shadow:0 2px 10px rgba(0,0,0,0.04);
+}