docs(coding-agent): reorganize session docs

packages/coding-agent/docs/docs.json

@@ -29,11 +29,7 @@
         },
         {
           "title": "Sessions",
-          "path": "session.md"
-        },
-        {
-          "title": "Session Tree",
-          "path": "tree.md"
+          "path": "sessions.md"
         },
         {
           "title": "Compaction",
@@ -74,6 +70,15 @@
         }
       ]
     },
+    {
+      "title": "Reference",
+      "items": [
+        {
+          "title": "Session Format",
+          "path": "session-format.md"
+        }
+      ]
+    },
     {
       "title": "Programmatic Usage",
       "items": [
@@ -129,5 +134,15 @@
         }
       ]
     }
+  ],
+  "redirects": [
+    {
+      "from": "session.md",
+      "to": "session-format.md"
+    },
+    {
+      "from": "tree.md",
+      "to": "sessions.md"
+    }
   ]
 }