Summary

Adds support for custom HTTP headers on all Playwright requests via environment variables. This enables backends to detect automated/LLM traffic and return optimized responses.

Closes #7

Configuration

Single header (common case):

PW_HEADER_NAME=X-Automated-By PW_HEADER_VALUE=playwright-skill

Multiple headers (JSON):

PW_EXTRA_HEADERS='{"X-Automated-By":"playwright-skill","X-Debug":"true"}'

Changes

• helpers.js: Add getExtraHeadersFromEnv() and update createContext() to merge env headers
• run.js: Inject getContextOptionsWithHeaders() utility in wrapper for raw Playwright API usage
• SKILL.md: Document custom headers feature
• API_REFERENCE.md: Add headers API reference
• Bump version to 4.1.0

Test plan

• Set PW_HEADER_NAME + PW_HEADER_VALUE and verify headers sent
• Set PW_EXTRA_HEADERS JSON and verify multiple headers sent
• Verify headers not sent when env vars not configured (backward compatible)
• Verify options.extraHTTPHeaders takes precedence over env vars