Add instance system guide nav (default off) with overview/options/hedge manual.

EOF

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

lib/common/static/instance_embed.js

@@ -15,6 +15,7 @@
     records: "/records",
     stats: "/stats",
     risk_policy: "/risk_policy",
+    system_guide: "/system_guide",
     env_config: "/env_config",
     settings: "/settings",
   };
@@ -296,7 +297,8 @@
   }
 
   function syncShellChrome(tab) {
-    const hideTopBar = tab === "settings" || tab === "risk_policy" || tab === "env_config";
+    const hideTopBar =
+      tab === "settings" || tab === "risk_policy" || tab === "system_guide" || tab === "env_config";
     document.querySelectorAll(".instance-top-bar").forEach((el) => {
       el.hidden = hideTopBar;
     });

lib/common/static/instance_settings_prefs.js

@@ -20,7 +20,7 @@
   }
 
   /** 默认关闭的导航开关:缺失时按 false,不能用 !== false */
-  const NAV_DEFAULT_OFF = { show_nav_dashboard: true };
+  const NAV_DEFAULT_OFF = { show_nav_dashboard: true, show_nav_system_guide: true };
 
   function navPrefShow(display, key) {
     if (!key) return true;
@@ -41,6 +41,7 @@
       "hedge-plan": "show_nav_hedge_plan",
       hedge_plan: "show_nav_hedge_plan",
       risk_policy: "show_nav_risk_policy",
+      system_guide: "show_nav_system_guide",
       env_config: "show_nav_env_config",
     };
     document.querySelectorAll(".embed-top-nav [data-embed-tab], .top-nav a[href^='/']").forEach((a) => {
@@ -68,6 +69,7 @@
       "hedge-plan": "show_nav_hedge_plan",
       hedge_plan: "show_nav_hedge_plan",
       risk_policy: "show_nav_risk_policy",
+      system_guide: "show_nav_system_guide",
       env_config: "show_nav_env_config",
     };
     const key = map[tab];