Reload copilot-instruction.md at runtime


### Discussed in https://github.com/github/copilot-cli/discussions/317

<div type='discussions-op-text'>

<sup>Originally posted by **MartinDelille** October 15, 2025</sup>
Is there a way to reload the .github/copilot-instruction.md when modified ? I currently need to quit and relaunch the tool.</div>