Summary

• remove Better Auth runtime and dependency footprint from web + backend
• make auth Clerk-only across Next app, Convex auth config, and provider wiring
• delete Better Auth components/helpers/tests/patch and update env/docs/CI references

Key Changes

• web auth flow now uses Clerk sign-in/sign-up and Clerk-backed Convex tokens
• /api/auth/[...all] replaced with explicit 404 stub (legacy endpoint removed)
• backend no longer registers Better Auth routes/components
• Convex auth config now uses Clerk issuer/audience envs only

Verification

• pnpm install
• pnpm -F web typecheck
• pnpm typecheck
• pnpm lint
• pnpm -F web test --run tests/auth/auth-smoke.test.ts tests/lib/rebuild-response.test.ts

Notes

• backend package-level tests were not run (no direct test script configured in packages/backend/package.json)