fix: validate the Node 24.9 runtime floor

scripts/command-entrypoints.compat.spec.ts

@@ -0,0 +1,24 @@
+/** Compatibility checks execute command entrypoints; importing helpers cannot detect a silent no-op. */
+
+import { spawnSync } from 'node:child_process'
+import { resolve } from 'node:path'
+import { describe, expect, it } from 'vitest'
+
+const root = resolve(import.meta.dirname, '..')
+
+describe('repository command entrypoints', () => {
+  it.each([
+    ['run-gates.ts', ['invalid-compat-mode'], 'run-gates: expected mode'],
+    ['build.ts', ['--scope', 'invalid-compat-scope'], 'build: --scope must be'],
+  ] as const)('executes %s argument validation on the running Node version', (script, args, diagnostic) => {
+    const child = spawnSync(process.execPath, ['--import', 'tsx/esm', resolve(root, 'scripts', script), ...args], {
+      cwd: root,
+      encoding: 'utf8',
+      timeout: 30_000,
+    })
+    expect(child.error).toBeUndefined()
+    expect(child.signal).toBeNull()
+    expect(child.status).toBe(1)
+    expect(child.stderr).toContain(diagnostic)
+  })
+})