db(T0): schema + migration 001 — super_oauth_id, firstname, lastname

tech-lead: overflow granted — gate migration avant Sprint B+C SuperOAuth

Backend/database/migrations/001_add_oauth_profile_fields.sql

@@ -0,0 +1,12 @@
+-- Migration 001 — Add OAuth + profile fields
+-- Safe: ADD COLUMN NULL only, no data loss
+-- Run: mysql -u <user> -p clickerz < migrations/001_add_oauth_profile_fields.sql
+
+ALTER TABLE users
+  ADD COLUMN IF NOT EXISTS firstname VARCHAR(50) NULL,
+  ADD COLUMN IF NOT EXISTS lastname VARCHAR(50) NULL,
+  ADD COLUMN IF NOT EXISTS super_oauth_id VARCHAR(36) NULL;
+
+-- Unique index separately (idempotent)
+CREATE UNIQUE INDEX IF NOT EXISTS uq_users_super_oauth_id
+  ON users (super_oauth_id);