ui(deploy): router blocker + DS dialog for unsaved edits

- Add deployedConfigSnapshot field to Deployment interface (mirrors server shape)
- Remove the Task 10.3 cast in handleRestore now that the type has the field
- New useUnsavedChangesBlocker hook (react-router useBlocker, v7.13.1)
- Wire AlertDialog into AppDeploymentPage for in-app navigation guard

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/src/api/queries/admin/apps.ts

@@ -41,6 +41,11 @@ export interface Deployment {
   deployedAt: string | null;
   stoppedAt: string | null;
   createdAt: string;
+  deployedConfigSnapshot?: {
+    jarVersionId: string;
+    agentConfig: Record<string, unknown> | null;
+    containerConfig: Record<string, unknown>;
+  } | null;
 }
 
 /**