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())
       )

src/hooks/edit-error-recovery/index.test.ts

@@ -102,6 +102,23 @@ describe("createEditErrorRecoveryHook", () => {
       })
     })
 
+    describe("#given MCP tool with undefined output.output", () => {
+      describe("#when output.output is undefined", () => {
+        it("#then should not crash", async () => {
+          const input = createInput("Edit")
+          const output = {
+            title: "Edit",
+            output: undefined as unknown as string,
+            metadata: {},
+          }
+
+          await hook["tool.execute.after"](input, output)
+
+          expect(output.output).toBeUndefined()
+        })
+      })
+    })
+
     describe("#given case insensitive tool name", () => {
       describe("#when tool is 'edit' lowercase", () => {
         it("#then should still detect and append reminder", async () => {