fix(pi): harden release proof lifecycle

tests/unit/pi-release-proof-cleanup.test.ts

@@ -0,0 +1,66 @@
+import { describe, expect, it } from 'vitest';
+
+import { runPiReleasePressureCleanup } from '../../electron/coding-runtime/pi/release-proof-cleanup';
+
+describe('PI release pressure cleanup', () => {
+  it('continues after an injected failure, reaches zero, and can be retried', async () => {
+    const counts = {
+      parentWorkers: 4,
+      childWorkers: 4,
+      liveProcessIds: 8,
+      providerRequests: 8,
+      processBudget: 8,
+      childPermits: 4,
+      dispatches: 4,
+      writeLeases: 4,
+    };
+    let failParentSettle = true;
+    const steps = [
+      { name: 'provider.release', run: () => { counts.providerRequests = 0; } },
+      {
+        name: 'dispatches.settle',
+        run: () => {
+          counts.childWorkers = 0;
+          counts.childPermits = 0;
+          counts.dispatches = 0;
+        },
+      },
+      {
+        name: 'parents.settle',
+        run: () => {
+          if (failParentSettle) {
+            failParentSettle = false;
+            throw new Error('injected parent settle failure');
+          }
+        },
+      },
+      {
+        name: 'pool.shutdown',
+        run: () => {
+          counts.parentWorkers = 0;
+          counts.liveProcessIds = 0;
+          counts.processBudget = 0;
+        },
+      },
+      { name: 'leases.release', run: () => { counts.writeLeases = 0; } },
+    ];
+
+    await expect(runPiReleasePressureCleanup(steps))
+      .rejects.toThrow('PI release pressure cleanup failed: parents.settle');
+    expect(Object.values(counts)).toEqual([0, 0, 0, 0, 0, 0, 0, 0]);
+
+    await expect(runPiReleasePressureCleanup(steps)).resolves.toBeUndefined();
+    expect(Object.values(counts)).toEqual([0, 0, 0, 0, 0, 0, 0, 0]);
+  });
+
+  it('bounds a hanging step and still runs later cleanup', async () => {
+    let released = false;
+    await expect(runPiReleasePressureCleanup([
+      { name: 'hang', run: async () => await new Promise(() => undefined) },
+      { name: 'release', run: () => { released = true; } },
+    ], { stepTimeoutMs: 10 })).rejects.toThrow(
+      'PI release pressure cleanup failed: hang',
+    );
+    expect(released).toBe(true);
+  });
+});