Fix mock isolation in remaining hook tests

- message-builder.test.ts: improve mock isolation
- background-update-check.ts: update for test compatibility
- execute-http-hook-security.test.ts: narrow mock targets
- recover-tool-result-missing.test.ts: prevent barrel contamination

🤖 GENERATED WITH ASSISTANCE OF OhMyOpenCode

src/hooks/anthropic-context-window-limit-recovery/message-builder.test.ts

@@ -4,7 +4,7 @@ const replaceEmptyTextPartsAsync = mock(() => Promise.resolve(false))
 const injectTextPartAsync = mock(() => Promise.resolve(false))
 const findMessagesWithEmptyTextPartsFromSDK = mock(() => Promise.resolve([] as string[]))
 
-mock.module("../../shared", () => ({
+mock.module("../../shared/normalize-sdk-response", () => ({
   normalizeSDKResponse: (response: { data?: unknown[] }) => response.data ?? [],
 }))