Rename @reviq/utils to @reviq/server-utils and add package READMEs

- Rename packages/utils/ to packages/server-utils/
- Update all imports and package.json references
- Add READMEs for frontend-utils, server-utils, and common packages
- Update main README with new package structure

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

apps/api-server/src/utils/password.ts

@@ -1,7 +1,7 @@
 import {
   hashPassword as hashPasswordUtil,
   verifyPassword as verifyPasswordUtil,
-} from "@reviq/utils";
+} from "@reviq/server-utils";
 import zxcvbn from "zxcvbn";
 
 export interface PasswordValidationResult {