Path-specific custom instructions not working in Agent mode

**When using Agent mode**, the `applyTo` filter that can be setup for [Path-specific custom copilot instructions](https://docs.github.com/en/copilot/how-tos/configure-custom-instructions/add-repository-instructions#creating-path-specific-custom-instructions-1) doesn't work.
As far as I can tell, the only `applyTo` value that worked for me was `**`.

This doesn't seem to work, for example:
```
---
applyTo: '**/*.swift'
---
Instruction here
```

From what I can see, Path-specific custom instructions don't even appear in the documentation, under the Xcode tab, but they appear as a feature in the app.

**Versions**
- Copilot for Xcode: 0.45.0
- Xcode: 26.1
- macOS: 26.1

**Steps to reproduce**
1. Create a new project
2. In Github Copilot settings, go to Advanced -> Under Custom Instructions -> Create
3. Enter a file name
4. In the prompted file, under the `applyTo` field, type something like `'**/*.swift'`
5. Add some test instructions
6. Open chat in a `swift` file, select agent mode.
7. See the agent not considering the instructions given at step 5.