(feat) auth

migrations/20251107073144_create_users_table.sql

@@ -0,0 +1,14 @@
+-- migrations/XXXXXX_create_users_table.sql
+
+CREATE TABLE IF NOT EXISTS users (
+    id SERIAL PRIMARY KEY,
+    username VARCHAR(50) UNIQUE NOT NULL,
+    password_hash TEXT NOT NULL,
+    bank_user_id VARCHAR(50) NOT NULL,  -- e.g., "team275-1"
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    
+    CONSTRAINT username_length CHECK (char_length(username) >= 3)
+);
+
+CREATE INDEX IF NOT EXISTS idx_users_username ON users(username);
+CREATE INDEX IF NOT EXISTS idx_users_bank_user_id ON users(bank_user_id);