Markdown渲染 + PRD需求文档(H Tab)

- mdRender(): 支持h1-h6/table/list/code/bold/link/blockquote/hr
- G 规范: dev-spec.md 以渲染后HTML展示
- H 需求: PRD.md 以渲染后HTML展示
- /api/prd: 新增路由读取PRD.md

gateway/scripts/dashboard.py

@@ -941,6 +941,29 @@ def api_spec():
         return jsonify({"ok": False, "error": str(e), "content": ""})
 
 
+@app.route("/api/prd")
+def api_prd():
+    """返回产品需求文档 (PRD) 内容"""
+    candidates = [
+        os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "..", "docs", "PRD.md"),
+        os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "docs", "PRD.md"),
+    ]
+    prd_path = None
+    for c in candidates:
+        p = os.path.normpath(c)
+        if os.path.exists(p):
+            prd_path = p
+            break
+    if not prd_path:
+        return jsonify({"ok": False, "error": "PRD.md not found", "content": ""})
+    try:
+        with open(prd_path, "r", encoding="utf-8") as f:
+            content = f.read()
+        return jsonify({"ok": True, "content": content, "path": prd_path})
+    except Exception as e:
+        return jsonify({"ok": False, "error": str(e), "content": ""})
+
+
 @app.route("/api/platform")
 @app.route("/api/health")
 def api_health():