refactor(edit): restructured edit tool with substring find and focused chunk rendering

- Reorganized edit tool from `patch/` to `edit/` directory with dedicated mode subdirectories (chunk, patch, hashline, replace).
- Replaced line-scoped edit operations with substring-based `find` parameter and added `replace_body` operation for preserving signatures.
- Added chunk focus modes (Expanded, Collapsed, Container) and focused rendering to display only touched chunks and adjacent siblings.
- Implemented notebook (ipynb) language support with virtual source conversion and cell-based chunk parsing.
- Enhanced chunk edit error messages with consistent checksum mismatch reporting and improved chunk selector auto-resolution.
- Extracted edit mode implementations into separate modules with improved helper functions and LSP integration for diagnostics.

packages/coding-agent/package.json

@@ -359,13 +359,17 @@
 			"types": "./src/modes/utils/*.ts",
 			"import": "./src/modes/utils/*.ts"
 		},
-		"./patch": {
-			"types": "./src/patch/index.ts",
-			"import": "./src/patch/index.ts"
+		"./edit": {
+			"types": "./src/edit/index.ts",
+			"import": "./src/edit/index.ts"
 		},
-		"./patch/*": {
-			"types": "./src/patch/*.ts",
-			"import": "./src/patch/*.ts"
+		"./edit/*": {
+			"types": "./src/edit/*.ts",
+			"import": "./src/edit/*.ts"
+		},
+		"./edit/modes/*": {
+			"types": "./src/edit/modes/*.ts",
+			"import": "./src/edit/modes/*.ts"
 		},
 		"./plan-mode/*": {
 			"types": "./src/plan-mode/*.ts",