Add database schema and Kysely packages

- Create initial database migration with full auth schema:
  - users, sessions, passkeys, devices tables
  - orgs, org_members, org_sites, org_invites tables
  - email_verifications, password_resets, login_requests tables
  - Indexes for common lookups and cleanup jobs
- Add @reviq/db-schema package with kysely-codegen
- Add @reviq/db package with Kysely client

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/db/src/index.ts

@@ -0,0 +1,26 @@
+/**
+ * Database client for RevIQ Publisher Dashboard
+ *
+ * @module @reviq/db
+ */
+
+import type { Kysely } from "kysely";
+import type { Database } from "@reviq/db-schema";
+import { createDb } from "./client.js";
+
+/**
+ * Default database instance
+ *
+ * Uses DATABASE_URL environment variable for connection
+ */
+export const db: Kysely<Database> = createDb();
+
+/**
+ * Export createDb for creating custom database instances
+ */
+export { createDb } from "./client.js";
+
+/**
+ * Re-export database types from db-schema
+ */
+export type { Database } from "@reviq/db-schema";