Rewrite extension management tools (#5057)

Signed-off-by: Angela Ning <aning@squareup.com>

crates/goose/src/agents/extension.rs

@@ -1,3 +1,4 @@
+use crate::agents::extension_manager_extension;
 use crate::agents::todo_extension;
 use std::collections::HashMap;
 
@@ -34,8 +35,8 @@ impl ProcessExit {
     }
 }
 
-pub static PLATFORM_EXTENSIONS: Lazy<HashMap<&'static str, PlatformExtensionDef>> =
-    Lazy::new(|| {
+pub static PLATFORM_EXTENSIONS: Lazy<HashMap<&'static str, PlatformExtensionDef>> = Lazy::new(
+    || {
         let mut map = HashMap::new();
 
         map.insert(
@@ -49,12 +50,28 @@ pub static PLATFORM_EXTENSIONS: Lazy<HashMap<&'static str, PlatformExtensionDef>
             },
         );
 
-        map
-    });
+        map.insert(
+            "extensionmanager",
+            PlatformExtensionDef {
+                name: extension_manager_extension::EXTENSION_NAME,
+                description:
+                    "Enable extension management tools for discovering, enabling, and disabling extensions",
+                default_enabled: true,
+                client_factory: |ctx| Box::new(extension_manager_extension::ExtensionManagerClient::new(ctx).unwrap()),
+            },
+        );
 
-#[derive(Debug, Clone)]
+        map
+    },
+);
+
+#[derive(Clone)]
 pub struct PlatformExtensionContext {
     pub session_id: Option<String>,
+    pub extension_manager:
+        Option<std::sync::Weak<crate::agents::extension_manager::ExtensionManager>>,
+    pub tool_route_manager:
+        Option<std::sync::Weak<crate::agents::tool_route_manager::ToolRouteManager>>,
 }
 
 #[derive(Debug, Clone)]