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/edit-error-recovery/hook.ts

@@ -44,7 +44,7 @@ export function createEditErrorRecoveryHook(_ctx: PluginInput) {
     ) => {
       if (input.tool.toLowerCase() !== "edit") return
 
-      const outputLower = output.output.toLowerCase()
+      const outputLower = (output.output ?? "").toLowerCase()
       const hasEditError = EDIT_ERROR_PATTERNS.some((pattern) =>
         outputLower.includes(pattern.toLowerCase())
       )