docs: update authentication documentation (#334)

* docs: update authentication documentation

- Fix region flag from --region us to --region usc
- Remove non-existent agentuity-auth template callout
- Add missing CLI commands (auth setup, auth secret)

Co-Authored-By: Rick Blalock <rickblalock@mac.com>

* fix: remove non-existent CLI commands (auth setup, auth secret)

Co-Authored-By: Rick Blalock <rickblalock@mac.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Rick Blalock <rickblalock@mac.com>

Author: devin-ai-integration[bot]

content/Frontend/authentication.mdx

@@ -13,15 +13,12 @@ The `@agentuity/auth` package provides authentication with built-in integration
 
 ```bash
 # Create a database (or use your own)
-agentuity cloud database create --region us
+agentuity cloud database create --region usc
 
 # Initialize auth (installs deps, generates src/auth.ts)
 agentuity project auth init
 ```
 
-<Callout type="info" title="Template Available">
-Start with auth pre-configured: `bunx agentuity create my-app --template agentuity-auth`
-</Callout>
 
 ### Server Setup