Add READMEs for remaining packages

- db-schema: Database schema types from kysely-codegen
- db: Database client and helper functions
- testing: Overview of testing packages
- test-helpers: Database testing utilities
- virtual-authenticator: WebAuthn virtual authenticator

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

packages/db/README.md

@@ -0,0 +1,33 @@
+# @reviq/db
+
+Database client and helper functions for the RevIQ platform.
+
+## Usage
+
+```typescript
+import { createDb } from "@reviq/db";
+
+const db = createDb(process.env.DATABASE_URL);
+
+// Use db with Kysely queries
+const users = await db.selectFrom("users").selectAll().execute();
+
+// Clean up when done
+await db.destroy();
+```
+
+## Exports
+
+### Client
+- `createDb(url)` - Create a Kysely database instance
+
+### Helper Functions
+- `executeBootstrap(trx, input)` - Bootstrap a new database with superuser and org
+- `generateToken()` - Generate an API token
+- `hashToken(token)` - Hash a token for storage
+- `parseToken(token)` - Parse and validate a token
+- `TOKEN_PREFIX` - The `reviq_` prefix for API tokens
+
+### Types
+- `Database` - Re-exported from `@reviq/db-schema`
+- `BootstrapInput` / `BootstrapResult` - Types for bootstrap operation