frontend/src/pages/Signup/index.js:16 wraps the form, animates submit states and exposes Google OAuth via onSubmitGoogle.
frontend/src/components/SignupForm/index.js:134 sends the primary POST /auth/signup request and persists temporary credentials in session storage for downstream OTP flows.
Unique ID and email availability are validated client-side using /s/cuid/{id} (frontend/src/components/SignupForm/index.js:209) and /s/uemail/{email} (frontend/src/components/SignupForm/index.js:190).
backend/r/auth_all.js:134 registers POST /auth/signupsocial for OAuth completions; controller_su.signup handles regular user creation.
backend/r/search.js:115 exposes GET /s/cuid/:cuid and backend/r/search.js:103 exposes the email lookup to support availability checks.
Verification emails are processed by POST /auth/verify-email/ (see backend/r/auth_all.js:216), moving records from users_unverified into the primary tables.