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/providers/index.ts

@@ -4,6 +4,7 @@ import {
 } from './anthropic';
 import { FalProvider } from './fal';
 import { GeminiGenerativeProvider, GeminiVertexProvider } from './gemini';
+import { MorphProvider } from './morph';
 import { OpenAIProvider } from './openai';
 import { PerplexityProvider } from './perplexity';
 
@@ -15,6 +16,7 @@ export const CopilotProviders = [
   PerplexityProvider,
   AnthropicOfficialProvider,
   AnthropicVertexProvider,
+  MorphProvider,
 ];
 
 export {