test(setup): align launch fixtures with runtime and host requirements

tests/acceptance/setup/launcherAliasesCli.test.ts

@@ -10,13 +10,21 @@ import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 import { cliTest } from "../../support/cli/cliFixture.js";
 
 cliTest.skipIf(process.platform === "win32")(
-  "migrates an owned shebang registration and starts its generated MCP command without PATH tools",
+  "migrates an owned shebang registration and starts its generated MCP command without a runtime on PATH",
   async ({ cli }) => {
     const home = await createTestTempDirectory("rea-registration-interpreter-");
     const profile = join(home, ".qwen");
     const config = join(profile, "settings.json");
     const entrypoint = resolve("scripts/rea.mjs");
-    const retainedEnvironment = { PATH: "", CALLER_SETTING: "keep exactly" };
+    const restrictedPath = join(home, "path-without-runtime");
+    await mkdir(restrictedPath);
+    // Linux process ownership requires procps; no JavaScript runtime is exposed.
+    if (process.platform === "linux")
+      await symlink("/bin/ps", join(restrictedPath, "ps"));
+    const retainedEnvironment = {
+      PATH: restrictedPath,
+      CALLER_SETTING: "keep exactly",
+    };
     const unrelated = { command: "other-server", args: ["keep"] };
     const original = JSON.stringify({
       mcpServers: {
@@ -34,7 +42,7 @@ cliTest.skipIf(process.platform === "win32")(
       HOME: home,
       USERPROFILE: home,
       QWEN_HOME: profile,
-      PATH: "",
+      PATH: restrictedPath,
       HOPPER_LAUNCHER_PATH: join(home, "missing-hopper"),
       GHIDRA_INSTALL_DIR: join(home, "missing-ghidra"),
       JAVA_HOME: join(home, "missing-java"),

tests/boundary/filesystem/clientConfigurationBom.test.ts

@@ -43,7 +43,7 @@ describe.each(["vscode", "copilot_cli", "opencode", "commandcode"])(
         await mkdir(dirname(client.configPath), { recursive: true });
         await writeFile(client.configPath, original);
         const currentCommandPath = join(home, "rea");
-        const command = [currentCommandPath, "mcp"];
+        const command = [process.execPath, currentCommandPath, "mcp"];
         expect(await inspectClientConfiguration(client, {}, command)).toEqual({
           status: "update",
           backupPath: `${client.configPath}.rea.backup`,

tests/boundary/filesystem/doctorSystemHostFilesystem.test.ts

@@ -23,7 +23,7 @@ it("threads the selected host and environment into system diagnostics", async ()
     environment,
     execFileOutput: async (command, arguments_, options) => {
       calls.push({ command, arguments: arguments_, environment: options?.env });
-      if (command === "sw_vers")
+      if (command === "/usr/bin/sw_vers")
         return {
           stdout: "15.0\n",
           stderr: "",
@@ -52,12 +52,12 @@ it("threads the selected host and environment into system diagnostics", async ()
   expect(host.platform).toBe("linux");
   expect(host.architecture).toBe("x64");
   await host.installationPaths?.();
-  await host.macosVersion();
+  expect(await host.macosVersion()).toBe("15.0");
   await host.executable(process.execPath);
 
   expect(calls.map(({ command }) => command)).toEqual([
     "which",
-    "sw_vers",
+    "/usr/bin/sw_vers",
     "ldd",
   ]);
   expect(