feat(app): /new-session route for new design (#31457)

packages/app/src/context/layout.tsx

@@ -77,6 +77,7 @@ export type ReviewDiffStyle = "unified" | "split"
 
 export type LayoutRoute =
   | { type: "home" }
+  | { type: "draft"; draftID: string; server?: ServerConnection.Key }
   | { type: "dir-new-sesssion"; dir: string; dirBase64: string; server?: ServerConnection.Key }
   | { type: "session"; dir: string; dirBase64: string; sessionId: string; server?: ServerConnection.Key }
 
@@ -120,10 +121,16 @@ const normalizeStoredSessionTabs = (key: string, tabs: SessionTabs) => {
   }
 }
 
-const currentRoute = (pathname: string): LayoutRoute => {
+const currentRoute = (pathname: string, search: string): LayoutRoute => {
   const parts = pathname.split("/").filter(Boolean)
   if (parts.length === 0) return { type: "home" }
 
+  if (parts[0] === "new-session") {
+    const draftID = new URLSearchParams(search).get("draftId")
+    if (!draftID) return { type: "home" }
+    return { type: "draft", draftID }
+  }
+
   const dirBase64 = parts[0]
   const dir = decode64(dirBase64)
   if (!dir) return { type: "home" }
@@ -145,7 +152,7 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
     const platform = usePlatform()
     const location = useLocation()
     const route = createMemo(() => {
-      const value = currentRoute(location.pathname)
+      const value = currentRoute(location.pathname, location.search)
       if (value.type === "home") return value
       return { ...value, server: server.key }
     })