Follow-up cleanup after #12188.

Changes:

• Centralize default exec approval timeout (CLI + gateway).
• Thread transport timeout separately (no opts mutation).
• Improve missing node:sqlite runtime error message.

Gate:

• fnm exec --using 22.21.1 -- pnpm check
• fnm exec --using 22.21.1 -- pnpm test

Greptile Overview

Greptile Summary

Refactored exec approval timeout handling to improve code maintainability and clarity.

• Centralized the 120-second default exec approval timeout as DEFAULT_EXEC_APPROVAL_TIMEOUT_MS constant, now shared between CLI and gateway
• Replaced opts object mutation pattern with explicit transportTimeoutMs parameter to callGatewayCli, avoiding spread operator overhead and making intent clearer
• Enhanced node:sqlite missing runtime error message to be more actionable for users
• Updated all tests to reflect the new API signature with separate transport timeout parameter

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• Clean refactoring with comprehensive test coverage. The changes eliminate object mutation, centralize magic numbers into well-named constants, and maintain functional equivalence with the previous implementation. All tests have been updated to match the new API signature. The SQLite error improvement is a pure developer experience enhancement with no logic changes.
• No files require special attention

_{Last reviewed commit: 179ed55}