Globally configurable allowed tools

### Describe the feature or problem you'd like to solve

Globally allowed tools within config.json

### Proposed solution

Similar to Claude Code, allowing permitted tools to be configurable at the global level.

eg. from Claude ~/.claude/settings.json
```
{
"permissions": {
"allow": [
"Bash(npm run lint)",
"Bash(npm run test:*)",
"Read(~/.zshrc)"
],
"deny": [
"Bash(curl:*)",
"Read(./.env)",
"Read(./.env.*)",
"Read(./secrets/**)"
]
}
}
```

This configuration will be used by every instance of Copilot CLI started

### Example prompts or workflows

I may want to make certain CLI commands available in every session (without needing to specify with CLI flags) eg.

`npm:*`
`go:*`
`git:diff:*`
`git:log:*`

### Additional context

_No response_