feat(FN-3504): add path mapping API with core contracts, routes, client hel

This merge introduces three major features: a full path-mapping API layer across core, dashboard, and desktop (FN-3504, four commits), shell multi-profile support with a new NativeShellConnectionManager component and connection manager onboarding flow (FN-3403), and migration of the WhatsApp plugin

Fusion-Task-Id: FN-3504

packages/dashboard/app/api-node.ts

@@ -4,7 +4,7 @@
  */
 
 import type { ProjectInfo } from "./api";
-import type { ProjectHealth, Task } from "@fusion/core";
+import type { ProjectHealth, ProjectNodePathMapping, Task } from "@fusion/core";
 import { api, proxyApi } from "./api";
 
 /** Health information for a remote node */
@@ -120,3 +120,8 @@ export async function syncNodeAuth(nodeId: string): Promise<NodeAuthSyncResult>
     body: JSON.stringify({}),
   });
 }
+
+/** Fetch all project path mappings for a node */
+export async function fetchNodeProjectPathMappings(nodeId: string): Promise<ProjectNodePathMapping[]> {
+  return api<ProjectNodePathMapping[]>(`/nodes/${encodeURIComponent(nodeId)}/path-mappings`);
+}