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/utils.ts

@@ -11,6 +11,7 @@ import {
 import { ZodType } from 'zod';
 
 import {
+  createDocEditTool,
   createDocKeywordSearchTool,
   createDocSemanticSearchTool,
   createExaCrawlTool,
@@ -382,6 +383,7 @@ export class CitationParser {
 }
 
 export interface CustomAITools extends ToolSet {
+  doc_edit: ReturnType<typeof createDocEditTool>;
   doc_semantic_search: ReturnType<typeof createDocSemanticSearchTool>;
   doc_keyword_search: ReturnType<typeof createDocKeywordSearchTool>;
   web_search_exa: ReturnType<typeof createExaSearchTool>;
@@ -459,6 +461,12 @@ export class TextStreamParser {
         );
         result = this.addPrefix(result);
         switch (chunk.toolName) {
+          case 'doc_edit': {
+            if (chunk.result && typeof chunk.result === 'object') {
+              result += `\n${chunk.result.result}\n`;
+            }
+            break;
+          }
           case 'doc_semantic_search': {
             if (Array.isArray(chunk.result)) {
               result += `\nFound ${chunk.result.length} document${chunk.result.length !== 1 ? 's' : ''} related to “${chunk.args.query}”.\n`;