This PR adds the ability to control the capabilities granted to
extensions by the extension host via the new
`granted_extension_capabilities` setting.
This setting is a list of the capabilities granted to any extension
running in Zed.
The currently available capabilities are:
- `process:exec` - Grants extensions the ability to invoke commands
using
[`zed_extension_api::process::Command`](https://docs.rs/zed_extension_api/latest/zed_extension_api/process/struct.Command.html)
- `download_file` - Grants extensions the ability to download files
using
[`zed_extension_api::download_file`](https://docs.rs/zed_extension_api/latest/zed_extension_api/fn.download_file.html)
- `npm:install` - Grants extensions the ability to install npm packages
using
[`zed_extension_api::npm_install_package`](https://docs.rs/zed_extension_api/latest/zed_extension_api/fn.npm_install_package.html)
Each of these capabilities has parameters that can be used to customize
the permissions.
For instance, to only allow downloads from GitHub, the `download_file`
capability can specify an allowed `host`:
```json
[
{ "kind": "download_file", "host": "github.com", "path": ["**"] }
]
```
The same capability can also be granted multiple times with different
parameters to build up an allowlist:
```json
[
{ "kind": "download_file", "host": "github.com", "path": ["**"] },
{ "kind": "download_file", "host": "gitlab.com", "path": ["**"] }
]
```
When an extension is not granted a capability, the associated extension
APIs protected by that capability will fail.
For instance, trying to use `zed_extension_api::download_file` when the
`download_file` capability is not granted will result in an error that
will be surfaced by the extension:
```
Language server phpactor:
from extension "PHP" version 0.4.3: failed to download file: capability for download_file https://github.com/phpactor/phpactor/releases/download/2025.07.25.0/phpactor.phar is not granted by the extension host
```
Release Notes:
- Added a `granted_extension_capabilities` setting to control the
capabilities granted to extensions.