Update

internal/store/migrations/0002_challenge_ip_user_logins.sql

@@ -0,0 +1,21 @@
+-- Add ip column to challenges (idempotent)
+DO $$
+BEGIN
+  IF NOT EXISTS (
+    SELECT 1 FROM information_schema.columns
+    WHERE table_schema = 'public' AND table_name = 'challenges' AND column_name = 'ip'
+  ) THEN
+    ALTER TABLE challenges ADD COLUMN ip TEXT;
+  END IF;
+END $$;
+
+-- User login history (ip, created_at per user)
+CREATE TABLE IF NOT EXISTS user_logins (
+  id SERIAL PRIMARY KEY,
+  public_key TEXT NOT NULL REFERENCES users(public_key) ON DELETE CASCADE,
+  ip TEXT NOT NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_user_logins_public_key ON user_logins(public_key);
+CREATE INDEX IF NOT EXISTS idx_user_logins_created_at ON user_logins(created_at);