feat: keyword sets, sponsorship signals, and extractor/profile fixes

Add per-profile keyword sets, job source settings, sponsorship signal pills,
and several ATS extractors. Fix Hiring Cafe discovery via Next.js SSR search,
profile activate for comma-separated basicAuthUser aliases, and resume path
backfill migrations. Update settings and hiring-cafe docs; localhost compose
overlay for loopback-only deploys.

.env.example

@@ -254,3 +254,19 @@ ADZUNA_APP_KEY=
 # Comma-separated paths under https://arc.dev used when seeding defaults (e.g. Playwright + Cypress feeds).
 # ARC_REMOTE_JOBS_PATHS=/remote-jobs/playwright,/remote-jobs/cypress
 # Prefer Settings for overrides: arcRemoteJobsPaths (JSON array), arcMaxJobsPerPath (default 120).
+
+# =============================================================================
+# New public job boards — optional (auto-enabled, no credentials)
+# =============================================================================
+# Caps via Settings: workingnomadsMaxJobsPerTerm, testdevjobsMaxJobsPerTerm,
+# testdevjobsMaxPages, builtinMaxJobsPerTerm, builtinMaxPagesPerTerm,
+# wellfoundMaxJobsPerTerm (Wellfound uses Camoufox when installed).
+
+# =============================================================================
+# Teamtailor / Huntflow / Factorial / Career pages — optional
+# =============================================================================
+# TEAMTAILOR_COMPANIES=testgorilla,polestar
+# HUNTFLOW_TENANTS=apicworld
+# FACTORIAL_TENANTS=yourbourse
+# CAREERS_PAGE_URLS=https://sentry.io/careers/,https://example.com/careers
+# Prefer Settings → Job sources & ATS for the same fields.