frontify: AI-optimize MCP action set

Frontify has no actions built in Pipedream today — there's nothing an agent can do with this integration yet. We'd like to build an initial action set so an agent can manage brand assets and guidelines, and so each tool is easy for an agent to configure.

A few things an agent can't do today, for example:
- Search or retrieve brand assets
- List asset libraries
- Update asset metadata
- Retrieve brand guideline content

**API reference:** https://developer.frontify.com/

Note: this integration uses a shared connection that Pipedream manages centrally, so scope changes aren't self-service — see the linked sub-issue for details.

**Add marker:**
When a component is AI-optimized, add this as the first line of the file:
```
// x-pd-ai: optimized
```
Add it to each action file and to the app's `.mjs` file.

Start with the Frontify API reference and inspect the integration's existing action files and app .mjs file. Add actions for searching or retrieving assets, listing asset libraries, updating asset metadata, and retrieving brand guideline content; done means each action and the app .mjs file begins with the specified AI-optimization marker.

Written by the indexing model from the issue text.