feat(bootstrap): implement bubblewrap sandbox argument builder and priority helper

crates/molotov-bootstrap/src/lib.rs

@@ -4,3 +4,4 @@ pub mod cdn;
 pub mod error;
 pub mod fflags;
 pub mod mods;
+pub mod sandbox;

crates/molotov-bootstrap/src/sandbox.rs

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use crate::error::MolotovError;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+#[derive(Debug, Clone)]
+pub struct SandboxConfig {
+    pub instance_id: String,
+    pub data_dir: PathBuf,
+    pub config_dir: PathBuf,
+    pub nice_priority: i32,
+}
+
+pub struct SandboxRunner {
+    config: SandboxConfig,
+}
+
+impl SandboxRunner {
+    pub fn new(config: SandboxConfig) -> Self {
+        Self { config }
+    }
+
+    pub fn build_bwrap_args(&self, executable_path: &Path) -> Vec<String> {
+        let mut args = vec![
+            "--unshare-pid".to_string(),
+            "--unshare-ipc".to_string(),
+            "--ro-bind".to_string(),
+            "/usr".to_string(),
+            "/usr".to_string(),
+            "--ro-bind".to_string(),
+            "/lib".to_string(),
+            "/lib".to_string(),
+            "--ro-bind".to_string(),
+            "/lib64".to_string(),
+            "/lib64".to_string(),
+            "--dev".to_string(),
+            "/dev".to_string(),
+            "--proc".to_string(),
+            "/proc".to_string(),
+            "--tmpfs".to_string(),
+            "/tmp".to_string(),
+        ];
+
+        // Isolated XDG_DATA_HOME
+        args.push("--bind".to_string());
+        args.push(self.config.data_dir.to_string_lossy().to_string());
+        args.push(self.config.data_dir.to_string_lossy().to_string());
+
+        // Isolated XDG_CONFIG_HOME
+        args.push("--bind".to_string());
+        args.push(self.config.config_dir.to_string_lossy().to_string());
+        args.push(self.config.config_dir.to_string_lossy().to_string());
+
+        args.push("--".to_string());
+        args.push(executable_path.to_string_lossy().to_string());
+
+        args
+    }
+
+    pub fn check_bwrap_installed() -> Result<(), MolotovError> {
+        match Command::new("bwrap").arg("--version").output() {
+            Ok(output) if output.status.success() => Ok(()),
+            _ => Err(MolotovError::Sandbox(
+                "bubblewrap ('bwrap') is not installed. Please install it via your system package manager."
+                    .to_string(),
+            )),
+        }
+    }
+}

crates/molotov-bootstrap/tests/sandbox_test.rs

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use molotov_bootstrap::sandbox::{SandboxConfig, SandboxRunner};
+use std::path::PathBuf;
+
+#[test]
+fn test_bwrap_arguments_contain_isolated_data_dir() {
+    let config = SandboxConfig {
+        instance_id: "test-acc-1".to_string(),
+        data_dir: PathBuf::from("/tmp/molotov_data"),
+        config_dir: PathBuf::from("/tmp/molotov_config"),
+        nice_priority: -5,
+    };
+
+    let runner = SandboxRunner::new(config);
+    let args = runner.build_bwrap_args(&PathBuf::from("/usr/bin/molotov"));
+
+    assert!(args.contains(&"--unshare-pid".to_string()));
+    assert!(args.contains(&"--bind".to_string()));
+    assert!(args.iter().any(|a| a.contains("/tmp/molotov_data")));
+}