tui: close open dialogs when navigating to a new session to prevent UI state from lingering

Author: thdxr

packages/opencode/src/cli/cmd/tui/feature-plugins/system/session-v2.tsx

@@ -997,6 +997,7 @@ const tui: TuiPlugin = async (api) => {
         const sessionID = currentSessionID(api)
         if (!sessionID) return
         api.route.navigate(route, { sessionID })
+        api.ui.dialog.clear()
       },
     },
   ])