fix: make goosed mcp paths container safe

capabilities.test.mjs

@@ -8,6 +8,7 @@ import {
   clampUserCapabilities,
   DEFAULT_USER_CAPABILITIES,
   normalizeCapabilityPatch,
+  resolveSandboxMcpNodeExecPath,
   resolveSandboxMcpServerPath,
   sandboxDeveloperTools,
   sandboxMcpTools,
@@ -20,6 +21,18 @@ test('resolveSandboxMcpServerPath resolves to an existing MCP entry file', () =>
   assert.ok(fs.existsSync(serverPath));
 });
 
+test('resolveSandboxMcpServerPath honors container-path override without host fs checks', () => {
+  assert.equal(
+    resolveSandboxMcpServerPath('/opt/portal/mindspace-sandbox-mcp.mjs'),
+    '/opt/portal/mindspace-sandbox-mcp.mjs',
+  );
+});
+
+test('resolveSandboxMcpNodeExecPath honors container-path override without host fs checks', () => {
+  assert.equal(resolveSandboxMcpNodeExecPath('/usr/local/bin/node'), '/usr/local/bin/node');
+  assert.equal(resolveSandboxMcpNodeExecPath(''), process.execPath);
+});
+
 test('default user policy blocks dangerous capabilities', () => {
   assert.equal(DEFAULT_USER_CAPABILITIES.shell, false);
   assert.equal(DEFAULT_USER_CAPABILITIES.filesystem, false);
@@ -222,6 +235,7 @@ test('static_publish with sandboxMcp uses stdio sandbox-fs extension instead of
   const sandboxExt = policy.extensionOverrides.find((ext) => ext.name === 'sandbox-fs');
   assert.ok(sandboxExt, 'sandbox-fs extension should be present');
   assert.equal(sandboxExt.type, 'stdio');
+  assert.equal(sandboxExt.cmd, process.execPath);
   assert.equal(sandboxExt.envs.SANDBOX_ROOT, '/opt/h5/MindSpace/abc123');
   assert.equal(sandboxExt.args[1], '/opt/h5/MindSpace/abc123'); // also passed as argv[2]
   assert.ok(sandboxExt.available_tools.includes('write_file'));
@@ -237,3 +251,17 @@ test('static_publish with sandboxMcp uses stdio sandbox-fs extension instead of
   assert.ok(!allTools.includes('write'), 'built-in write should not be exposed');
   assert.ok(!allTools.includes('shell'), 'shell should not be exposed');
 });
+
+test('sandboxMcp honors container node executable override', () => {
+  const caps = { ...DEFAULT_USER_CAPABILITIES, static_publish: true };
+  const policy = buildAgentExtensionPolicy(caps, {
+    sandboxMcp: {
+      serverPath: '/opt/h5/mindspace-sandbox-mcp.mjs',
+      sandboxRoot: '/opt/h5/MindSpace/abc123',
+      nodeExecPath: '/usr/local/bin/node',
+    },
+  });
+
+  const sandboxExt = policy.extensionOverrides.find((ext) => ext.name === 'sandbox-fs');
+  assert.equal(sandboxExt?.cmd, '/usr/local/bin/node');
+});