Reuse firecrawl-cli login: credentials.json fallback for API key

[rakshith48]

Lets a user who ran firecrawl login use the plugin with no env var — the plugin reads the API key the CLI stored.

Resolution order (env always wins)

1. FIRECRAWL_API_KEY (+ FIRECRAWL_API_URL) env
2. firecrawl-cli credentials.json — per-OS path mirrored from cli/src/utils/credentials.ts (macOS ~/Library/Application Support/firecrawl-cli, Linux ~/.config/firecrawl-cli, Windows %AppData%/firecrawl-cli)
3. Clear error: set FIRECRAWL_API_KEY or run firecrawl login

The CLI's browser login resolves to a real fc- API key and saves { apiKey, apiUrl }, so the same key works for both browser.provider and command.run.

Why reading the file is safe here

It's a stable, documented shape (StoredCredentials = { apiKey?, apiUrl? }), deterministic per-OS path, chmod 0600. Treated as a best-effort fallback: missing/corrupt → falls through to the env-var contract. Never logged.

Verification

• node --test 12/12 (incl. file-fallback + env-overrides-file, isolated temp HOMEs).
• Live: env path, credentials.json fallback (env unset → key from file → real session), no-creds error, and full agent-browser drive (open/snapshot/click/close + scrape), 0 leaked sessions.

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Plugin now reads stored CLI credentials as fallback when environment variables aren't configured.
  • API credentials are resolved dynamically per API call, enabling credential changes between requests.

• Documentation

  • Added credential resolution guide clarifying configuration priority and setup methods.
  • Improved error messages to help guide users through credential configuration.

[coderabbitai]

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📒 Files selected for processing (3)

• README.md
• bin/plugin.js
• test/plugin.test.js

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/cli-credential-fallback

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