refactor: remove inline definitions from ManifestSchema for cleaner structure

Author: hotlong

content/docs/references/system/manifest/Manifest.mdx

@@ -14,7 +14,6 @@ description: Manifest Schema Reference
 | **description** | `string` | optional | Package description |
 | **permissions** | `string[]` | optional | Array of required permission strings |
 | **objects** | `string[]` | optional | Glob patterns for ObjectQL schemas files |
-| **definitions** | `object` | optional | Inline resource definitions (for serverless/compiled runtimes) |
 | **datasources** | `string[]` | optional | Glob patterns for Datasource definitions |
 | **dependencies** | `Record<string, string>` | optional | Package dependencies |
 | **configuration** | `object` | optional | Plugin configuration settings |