feat: add v03 user billing service (#1128)

internal/userbilling/migrations/0001_user_billing.sql

@@ -0,0 +1,105 @@
+CREATE TABLE IF NOT EXISTS hwlab_users (
+  id TEXT PRIMARY KEY,
+  email TEXT NOT NULL UNIQUE,
+  username TEXT NOT NULL UNIQUE,
+  display_name TEXT NOT NULL DEFAULT '',
+  password_hash TEXT NOT NULL,
+  status TEXT NOT NULL DEFAULT 'active',
+  role TEXT NOT NULL DEFAULT 'user',
+  email_verified BOOLEAN NOT NULL DEFAULT FALSE,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  CHECK (status IN ('active', 'disabled', 'pending')),
+  CHECK (role IN ('user', 'admin'))
+);
+
+CREATE TABLE IF NOT EXISTS hwlab_user_sessions (
+  id TEXT PRIMARY KEY,
+  user_id TEXT NOT NULL REFERENCES hwlab_users(id) ON DELETE CASCADE,
+  token_hash TEXT NOT NULL UNIQUE,
+  expires_at TIMESTAMPTZ NOT NULL,
+  revoked_at TIMESTAMPTZ,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS hwlab_user_sessions_user_id_idx ON hwlab_user_sessions(user_id);
+CREATE INDEX IF NOT EXISTS hwlab_user_sessions_token_hash_idx ON hwlab_user_sessions(token_hash);
+
+CREATE TABLE IF NOT EXISTS hwlab_api_keys (
+  id TEXT PRIMARY KEY,
+  user_id TEXT NOT NULL REFERENCES hwlab_users(id) ON DELETE CASCADE,
+  name TEXT NOT NULL,
+  key_prefix TEXT NOT NULL,
+  key_hash TEXT NOT NULL UNIQUE,
+  scopes_json JSONB NOT NULL DEFAULT '["api"]'::jsonb,
+  status TEXT NOT NULL DEFAULT 'active',
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  last_used_at TIMESTAMPTZ,
+  revoked_at TIMESTAMPTZ,
+  CHECK (status IN ('active', 'revoked'))
+);
+
+CREATE INDEX IF NOT EXISTS hwlab_api_keys_user_id_idx ON hwlab_api_keys(user_id);
+CREATE INDEX IF NOT EXISTS hwlab_api_keys_key_hash_idx ON hwlab_api_keys(key_hash);
+
+CREATE TABLE IF NOT EXISTS hwlab_credit_accounts (
+  user_id TEXT PRIMARY KEY REFERENCES hwlab_users(id) ON DELETE CASCADE,
+  balance_credits BIGINT NOT NULL DEFAULT 0,
+  reserved_credits BIGINT NOT NULL DEFAULT 0,
+  plan_id TEXT NOT NULL DEFAULT 'default',
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  CHECK (balance_credits >= 0),
+  CHECK (reserved_credits >= 0)
+);
+
+CREATE TABLE IF NOT EXISTS hwlab_credit_ledger (
+  id TEXT PRIMARY KEY,
+  user_id TEXT NOT NULL REFERENCES hwlab_users(id) ON DELETE CASCADE,
+  delta_credits BIGINT NOT NULL,
+  balance_after BIGINT NOT NULL,
+  kind TEXT NOT NULL,
+  reason TEXT NOT NULL DEFAULT '',
+  idempotency_key TEXT UNIQUE,
+  metadata JSONB NOT NULL DEFAULT '{}'::jsonb,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS hwlab_credit_ledger_user_id_idx ON hwlab_credit_ledger(user_id);
+
+CREATE TABLE IF NOT EXISTS hwlab_billing_reservations (
+  id TEXT PRIMARY KEY,
+  user_id TEXT NOT NULL REFERENCES hwlab_users(id) ON DELETE CASCADE,
+  service_id TEXT NOT NULL,
+  estimated_credits BIGINT NOT NULL,
+  estimated_tokens BIGINT NOT NULL DEFAULT 0,
+  status TEXT NOT NULL DEFAULT 'reserved',
+  idempotency_key TEXT UNIQUE,
+  metadata JSONB NOT NULL DEFAULT '{}'::jsonb,
+  expires_at TIMESTAMPTZ NOT NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  CHECK (estimated_credits >= 0),
+  CHECK (estimated_tokens >= 0),
+  CHECK (status IN ('reserved', 'completed', 'cancelled', 'expired'))
+);
+
+CREATE INDEX IF NOT EXISTS hwlab_billing_reservations_user_id_idx ON hwlab_billing_reservations(user_id);
+
+CREATE TABLE IF NOT EXISTS hwlab_usage_records (
+  id TEXT PRIMARY KEY,
+  reservation_id TEXT REFERENCES hwlab_billing_reservations(id) ON DELETE SET NULL,
+  user_id TEXT NOT NULL REFERENCES hwlab_users(id) ON DELETE CASCADE,
+  service_id TEXT NOT NULL,
+  unit TEXT NOT NULL DEFAULT 'token',
+  quantity BIGINT NOT NULL DEFAULT 0,
+  credits BIGINT NOT NULL DEFAULT 0,
+  idempotency_key TEXT UNIQUE,
+  metadata JSONB NOT NULL DEFAULT '{}'::jsonb,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  CHECK (quantity >= 0),
+  CHECK (credits >= 0)
+);
+
+CREATE INDEX IF NOT EXISTS hwlab_usage_records_user_id_idx ON hwlab_usage_records(user_id);
+CREATE INDEX IF NOT EXISTS hwlab_usage_records_service_id_idx ON hwlab_usage_records(service_id);
+