gong: AI-optimize MCP action set

Gong today can add a call, list calls, pull extensive data, and retrieve transcripts (plus a dropdown helper). An agent can get raw data but can't easily get to the insights. We'd like these improved and new tools added so an agent can work with calls and deals more directly, and so each tool is easy for an agent to reach for and get right.

A few things an agent can't do today, for example:
- Find calls by account, rep, or date — e.g. "Acme calls this quarter"
- Get a call's summary, topics, or next steps
- Pull the deal or pipeline data tied to calls
- Search transcripts for a keyword
- List users or teams

**API reference:** https://gong.app.gong.io/settings/api/documentation#overview

**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.