[ios] investigate iOS specific AI agent set up #188285

Use case

For some background, I have been using Antigravity's agent skills for an internal project, and it is pretty convenient, that I simply select the agent from the agent dropdown menu in Antigravity's chat box, and then my iOS skills are automatically loaded.

This setup could be helpful for Flutter contributors when working on iOS specific tasks, and help avoid wasting tokens for non-iOS tasks. A similar agent would be the existing android agent, mentioned here:

... our goal is to maintain curated, persona- or team-based collections of skills ...

Proposal

A few strawman ideas of iOS-specific skills:

Strawman Idea 1: Adding a new menu item to the context menu
We have been adding new items to the context menu quite a few times (e.g. look up, scan, etc). We can provide extra instruction how to add to both Flutter-rendered menu and the native menu (both are needed)

Strawman Idea 2: Checking Swift concurrency annotations for ObjC APIs.
We can use it to assist our current project to annotate existing ObjC APIs, and for new ObjC APIs in the future.

This one can be interesting, since we may want to deviate from Apple's practice for ObjC protocols: We recently proved that certain practice from Apple could result in a breaking change.

(well this also applies to macOS embedder, so maybe create darwin-agent rather than ios-agent? open to discussion)

Strawman Idea 3: Running iOS specific tests

We can cover iOS related unit tests, integration tests, etc.

If a test requires multiple steps (e.g. I frequently build the wrong engine for unit test), we can include a few scripts to make things easier.

Strawman Idea X: Feel free to comment with more ideas

Note that these skills will only be loaded when developing on iOS specific tasks (aka the team-based collections of skills from README. We don't want to put them under our global skills, since contributors on Android shouldn't waste tokens discovering these skills at all.

A drawback is that you have to select the agent from Antigravity's drop-down menu, rather than using the default Main Agent. It is unknown whether this is a habit that iOS contributors want to pick up. Though it is worth exploring the idea.