Refactor verify endpoint timeout handling and improve fetch robustness

[GsCommand]

Summary

This PR refactors the /verify endpoint to use explicit timeout guards instead of Promise.race(), improves doFetch() body handling with a fallback for runtimes lacking getReader(), and adds security/operational documentation.

Key Changes

Core Logic Improvements

• Verify endpoint timeout handling: Replaced Promise.race() pattern with a setTimeout guard and responded flag to prevent double-response races. The timeout now fires independently and guards all response paths (success, error, and schema validation).

• Fetch body handling: Added fallback logic in doFetch() for runtimes where resp.body.getReader() is unavailable. Falls back to resp.text() when streaming is not supported, ensuring consistent behavior across environments.

• Simplified buffer concatenation: Removed conditional logic that fell back to resp.text() after streaming; now always uses Buffer.concat() on the collected chunks.

Documentation & Configuration

• Added SECURITY.md: Vulnerability reporting policy, supported versions, and hardening guidance (key protection, debug route gating, CORS restriction, SSRF guard, HTTPS, dependency pinning).

• Added LICENSE: MIT license matching protocol-commons.

• Updated package.json: Added description, license field, repository metadata, and Node.js engine requirement (>=20.0.0).

• Updated REVIEW.md: Converted from risk-focused to resolution-focused format, documenting all prior issues now addressed (CORS, debug routes, request validation, double-response race, fetch body consumption).

• Enhanced CI workflow: Added branch filters and npm audit check for high-severity vulnerabilities.

• Fixed .gitignore: Removed overly broad *.json rule that blocked package.json tracking; now only ignores node_modules/.

Implementation Details

• The verify endpoint now uses a top-level setTimeout that fires after VERIFY_MAX_MS, setting responded = true and sending a 500 error if no response has been sent yet.
• A send() helper clears the timer and checks the responded flag before sending, ensuring only one response is ever sent.
• The fail() helper now calls send() instead of directly calling res.status().json().
• Fetch fallback gracefully handles both streaming and non-streaming response bodies, maintaining byte-limit enforcement in both paths.

https://claude.ai/code/session_01Jh9WXqejeBVXesWCkpt9an