Add feature to make the runtime immutable

This prevents installing and uninstalling the runtime using commands, and also stops patching the runtime when launching web apps. The runtime can still be patched manually from the extension settings or the patch command if the user has sufficient write permissions to do so.

This is meant for immutable systems like Guix or Nix where runtime might be provided by the package manager and pre-patched. See #204 for more.

native/Cargo.toml

@@ -22,6 +22,7 @@ lto = true
 [features]
 portable = ["dep:phf"]
 static = ["reqwest/native-tls-vendored", "bzip2/static"]
+immutable-runtime = []
 
 [dependencies]
 ab_glyph = "0.2.23"

native/src/components/runtime.rs

@@ -187,6 +187,7 @@ impl Runtime {
         Ok(Self { version, directory, executable, config })
     }
 
+    #[cfg(not(feature = "immutable-runtime"))]
     pub fn install(self) -> Result<()> {
         const TEMP_FILE_ERROR: &str = "Failed to create a temporary file";
         const DOWNLOAD_ERROR: &str = "Failed to download the runtime";
@@ -269,6 +270,7 @@ impl Runtime {
         Ok(())
     }
 
+    #[cfg(not(feature = "immutable-runtime"))]
     pub fn uninstall(self) -> Result<()> {
         info!("Uninstalling the runtime");
         remove_dir_contents(self.directory).context("Failed to remove runtime directory")?;

native/src/console/runtime.rs

@@ -7,6 +7,7 @@ use crate::console::Run;
 use crate::directories::ProjectDirs;
 
 impl Run for RuntimeInstallCommand {
+    #[cfg(not(feature = "immutable-runtime"))]
     fn run(&self) -> Result<()> {
         cfg_if! {
             if #[cfg(platform_windows)] {
@@ -31,15 +32,26 @@ impl Run for RuntimeInstallCommand {
 
         Ok(())
     }
+
+    #[cfg(feature = "immutable-runtime")]
+    fn run(&self) -> Result<()> {
+        anyhow::bail!("Cannot install runtime when the immutable runtime feature is enabled")
+    }
 }
 
 impl Run for RuntimeUninstallCommand {
+    #[cfg(not(feature = "immutable-runtime"))]
     fn run(&self) -> Result<()> {
         let dirs = ProjectDirs::new()?;
         let runtime = Runtime::new(&dirs)?;
 
         runtime.uninstall().context("Failed to uninstall runtime")
     }
+
+    #[cfg(feature = "immutable-runtime")]
+    fn run(&self) -> Result<()> {
+        anyhow::bail!("Cannot uninstall runtime when the immutable runtime feature is enabled")
+    }
 }
 
 impl Run for RuntimePatchCommand {

native/src/console/site.rs

@@ -78,6 +78,7 @@ impl Run for SiteLaunchCommand {
         };
 
         if should_patch {
+            #[cfg(not(feature = "immutable-runtime"))]
             runtime.patch(&dirs, Some(site))?;
             profile.patch(&dirs)?;
         }