Clean public positioning and add local-first persistence

[leini8891]

Summary

• Remove public-facing internal/TinyFish positioning and neutralize demo defaults.
• Add configurable role, salary, experience, notice-period, work-authorization, visa-sponsorship, and relocation preferences.
• Persist fallback local data to local_workspace/applypilot-store.json when Supabase is not configured.

Verification

• pnpm check
• pnpm test
• pnpm build
• pnpm test:e2e

Notes

• Build still falls back gracefully when the local Supabase host in .env.local cannot resolve.