feat(server): add morph doc edit tool (#12789)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Introduced support for the Morph provider in the copilot module,
enabling integration with the Morph LLM API.
- Added a new document editing tool that allows users to propose and
apply edits to existing documents via AI assistance.
- **Configuration**
- Added configuration options for the Morph provider in both backend and
admin interfaces.
- **Enhancements**
- Expanded tool support to include document editing capabilities within
the copilot feature set.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/config.ts

@@ -9,6 +9,7 @@ import {
 } from './providers/anthropic';
 import type { FalConfig } from './providers/fal';
 import { GeminiGenerativeConfig, GeminiVertexConfig } from './providers/gemini';
+import { MorphConfig } from './providers/morph';
 import { OpenAIConfig } from './providers/openai';
 import { PerplexityConfig } from './providers/perplexity';
 import { VertexSchema } from './providers/types';
@@ -31,6 +32,7 @@ declare global {
         perplexity: ConfigItem<PerplexityConfig>;
         anthropic: ConfigItem<AnthropicOfficialConfig>;
         anthropicVertex: ConfigItem<AnthropicVertexConfig>;
+        morph: ConfigItem<MorphConfig>;
       };
     };
   }
@@ -82,6 +84,10 @@ defineModuleConfig('copilot', {
     default: {},
     schema: VertexSchema,
   },
+  'providers.morph': {
+    desc: 'The config for the morph provider.',
+    default: {},
+  },
   unsplash: {
     desc: 'The config for the unsplash key.',
     default: {