Add wait-for, cookies, and wait-timeout for authenticated dashboards (v2.2.0)

[Helvio88]

Summary

Makes web-screenshot usable on login-gated / slow SPA dashboards generically, using CLI flags and batch-file lines only. No environment variables.

Wait for a selector

• -s / --wait-for <selector> calls Puppeteer page.waitForSelector after networkidle2
• --wait-timeout [s] (default 30, clamped 1–600) is that wait
• Existing -t extra wait still runs after the selector (or after idle if no selector)

Cookie / session auth

• --cookies <file> loads cookies before navigation
• Accepts a JSON array of Puppeteer cookies, Playwright storageState JSON, or a Netscape cookie file
• Cookies missing url and domain use the screenshot URL
• Existing -a / --auth user:pass still does HTTP basic/NTLM via page.authenticate

Batch

New flags work on batch lines the same way as other options (quote-aware parser).

Docs / version

• README examples use https://example.com / dashboard language only
• Flags only — no WEB_SCREENSHOT_* or other env fallbacks
• CHANGELOG + version 2.2.0
• Not published to npm

Test plan

• npm test (no live network; mocked browser)
• Unit tests for wait-for planning, env ignored vs flags, cookie file load (JSON array, storageState, Netscape)
• Batch parser accepts --wait-for, --wait-timeout, --cookies, quoted selectors
• Lint, typecheck, and dist/ rebuild match CI