fix: migrate workspace/project IDs to string and widen schema enums

- Change workspace id/projectId from z.number() to z.union([z.string(), z.number()]).transform(String) for backward compat
- Add "non_git" to projectKind, "local_checkout" to workspaceKind enums
- Session converts numeric IDs to strings at the descriptor boundary
- Update tests and daemon-client event types to match

packages/server/src/client/daemon-client.ts

@@ -127,7 +127,7 @@ export type DaemonEvent =
     }
     | {
       type: "workspace_update";
-      workspaceId: number;
+      workspaceId: string;
       payload: Extract<SessionOutboundMessage, { type: "workspace_update" }>["payload"];
     }
   | {