Add provider integrations and Firecrawl workflows

[eaczydot]

Summary

• finish and verify the global Inter typography rollout
• add Raycast-compatible provider favicons with an offline local fallback
• add the Firecrawl BYOK runtime with bounded credit policies, cancellation, and trusted workflow contracts
• add the complete Firecrawl slash-command catalog, deterministic setup forms, and exact-match routing

Why

This turns the existing provider integration plans into a working, safety-bounded implementation while preserving ordinary AppLess behavior when Firecrawl is unavailable.

Safety

• Firecrawl credentials remain provider-scoped and stored on-device
• every Agent run uses a central explicit maxCredits policy and confirmation
• speculative prefetch cannot execute paid Firecrawl calls
• unknown or partial slash commands never execute or fall through to generic generation
• provider favicons always retain a local offline fallback

Validation

• npm run typecheck
• npm test -- --runInBand --no-watchman — 8 suites, 91 tests passed
• git diff --check 555fc59 HEAD
• npm ls @raycast/api @raycast/utils — both absent