fix: guard output.output in tool after-hooks for MCP tools (#1720)

MCP tool responses can have undefined output.output, causing TypeError
crashes in tool.execute.after hooks.

Changes:
- comment-checker/hook.ts: guard output.output with ?? '' before toLowerCase()
- edit-error-recovery/hook.ts: guard output.output with ?? '' before toLowerCase()
- task-resume-info/hook.ts: extract output.output ?? '' into outputText before all string operations
- Added tests for undefined output.output in edit-error-recovery and task-resume-info

src/hooks/comment-checker/hook.ts

@@ -92,7 +92,7 @@ export function createCommentCheckerHooks(config?: CommentCheckerConfig) {
       const toolLower = input.tool.toLowerCase()
 
       // Only skip if the output indicates a tool execution failure
-      const outputLower = output.output.toLowerCase()
+      const outputLower = (output.output ?? "").toLowerCase()
       const isToolFailure =
         outputLower.includes("error:") ||
         outputLower.includes("failed to") ||