feat: enhance partial diff failure reporting and visibility

- Improved error reporting for partial diff failures
- Added prominent warning messages when some diffs fail to apply
- Enhanced visibility with clear status indicators (X/Y format)
- Preserved existing X/Y visual indicators in progress status

Fixes #9444
Related to #9305

src/core/tools/ApplyDiffTool.ts

@@ -238,7 +238,25 @@ export class ApplyDiffTool extends BaseTool<"apply_diff"> {
 			let partFailHint = ""
 
 			if (diffResult.failParts && diffResult.failParts.length > 0) {
-				partFailHint = `But unable to apply all diff parts to file: ${absolutePath}, silently use <read_file> tool to check newest file version and re-apply diffs\n`
+				// Enhanced error reporting for partial failures
+				const totalDiffs = (diffContent.match(/<<<<<<< SEARCH/g) || []).length
+				const failedDiffs = diffResult.failParts.filter((part) => !part.success).length
+				const successfulDiffs = totalDiffs - failedDiffs
+
+				partFailHint = `⚠️ Partial diff application: ${successfulDiffs}/${totalDiffs} diffs applied successfully to ${getReadablePath(task.cwd, relPath)}\n`
+				partFailHint += `Failed to apply ${failedDiffs} diff(s). Please review the file and retry failed changes.\n`
+
+				// Report the partial failure prominently with enhanced visibility
+				const partialFailureMessage =
+					`⚠️ PARTIAL DIFF APPLICATION\n` +
+					`━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n` +
+					`File: ${getReadablePath(task.cwd, relPath)}\n` +
+					`Status: ${successfulDiffs}/${totalDiffs} diffs applied successfully\n` +
+					`Failed: ${failedDiffs} diff(s) could not be applied\n` +
+					`━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n` +
+					`Action Required: Review the file and retry failed changes`
+
+				await task.say("error", partialFailureMessage)
 			}
 
 			// Get the formatted response message

src/core/tools/MultiApplyDiffTool.ts

@@ -694,14 +694,29 @@ ${errorDetails ? `\nTechnical details:\n${errorDetails}\n` : ""}
 				let partFailHint = ""
 
 				if (successCount < diffItems.length) {
-					partFailHint = `Unable to apply all diff parts to file: ${absolutePath}`
+					// Enhanced error reporting for partial failures
+					const failedCount = diffItems.length - successCount
+					partFailHint = `⚠️ Partial diff application: ${successCount}/${diffItems.length} diffs applied successfully to ${getReadablePath(cline.cwd, relPath)}\n`
+					partFailHint += `Failed to apply ${failedCount} diff(s). Please review the file and retry failed changes.\n`
+
+					// Report the partial failure prominently with enhanced visibility
+					const partialFailureMessage =
+						`⚠️ PARTIAL DIFF APPLICATION\n` +
+						`━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n` +
+						`File: ${getReadablePath(cline.cwd, relPath)}\n` +
+						`Status: ${successCount}/${diffItems.length} diffs applied successfully\n` +
+						`Failed: ${failedCount} diff(s) could not be applied\n` +
+						`━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n` +
+						`Action Required: Review the file and retry failed changes`
+
+					await cline.say("error", partialFailureMessage)
 				}
 
 				// Get the formatted response message
 				const message = await cline.diffViewProvider.pushToolWriteResult(cline, cline.cwd, !fileExists)
 
 				if (partFailHint) {
-					results.push(partFailHint + "\n" + message)
+					results.push(partFailHint + message)
 				} else {
 					results.push(message)
 				}