test(orcad): pin the node-pty precondition to ground truth, not a prepared host

CI's test shard runs `vitest` directly, so `ensure-native-runtime --runtime=node`
never prepares node-pty for the Node ABI — `degraded` is the correct verdict
there, and asserting 'ok' encoded an environment the shard does not have.

Asserting whatever it returned would be vacuous, so the expectation is now
derived from an independent require() of node-pty. Verified it still bites:
forcing the precondition to always report 'ok' fails the suite.

src/main/orcad/node-pty-precondition.test.ts

@@ -112,7 +112,7 @@ describe('classifyNodePtyProbeResult', () => {
   it('reads past node\u2019s echoed source line when it can only use stderr', () => {
     const failure = probe({
       stderr:
-        "[eval]:1\nprocess.dlopen({exports:{}},f);\n        ^\n\nError: something specific went wrong\n"
+        '[eval]:1\nprocess.dlopen({exports:{}},f);\n        ^\n\nError: something specific went wrong\n'
     })
     expect(failure?.detail).toBe('Error: something specific went wrong')
   })
@@ -179,9 +179,21 @@ describe('checkNodePtyPrecondition', () => {
     expect(verdict).toMatchObject({ status: 'blocked', reason: 'dependency_missing' })
   })
 
-  it('passes against the node-pty this repo actually builds', () => {
+  it('agrees with whether node-pty actually loads on this host', () => {
+    // Why compared against ground truth rather than asserted as 'ok': CI's test shard
+    // runs `vitest` directly, so `ensure-native-runtime --runtime=node` never prepares
+    // node-pty for the Node ABI and `degraded` is the CORRECT verdict there. Asserting
+    // 'ok' encoded a prepared environment the shard does not have. Asserting "whatever
+    // it said" would be vacuous, so this pins the verdict to an independent check.
+    let loads = true
+    try {
+      createRequire(import.meta.url)('node-pty')
+    } catch {
+      loads = false
+    }
+
     const verdict = checkNodePtyPrecondition({ prebuildsDir: null })
-    expect(verdict.status).toBe('ok')
+    expect(verdict.status).toBe(loads ? 'ok' : 'degraded')
     expect(verdict.slot).toBe(
       process.platform === 'linux'
         ? `linux-${process.arch}-${verdict.abi.libc}`
@@ -210,7 +222,9 @@ describe('checkNodePtyPrecondition', () => {
     const dir = stageNodePty()
     const abi = detectNativeHostAbi()
     const slot =
-      abi.libc === 'none' ? `${abi.platform}-${abi.arch}` : `${abi.platform}-${abi.arch}-${abi.libc}`
+      abi.libc === 'none'
+        ? `${abi.platform}-${abi.arch}`
+        : `${abi.platform}-${abi.arch}-${abi.libc}`
     const prebuildsDir = mkdtempSync(join(tmpdir(), 'orcad-prebuilds-'))
     temporaryDirs.push(prebuildsDir)
     mkdirSync(join(prebuildsDir, slot), { recursive: true })