fix: make dedup test platform-aware for Windows PATHEXT

On Windows, findOnPath checks 4 candidate names per directory
(patchloom.exe, .cmd, .bat, patchloom) via PATHEXT. The dedup test
asserted exactly 1 fs.access call, which is correct on Unix but
fails on Windows where 4 candidates are checked per unique directory.

Make the expected count platform-aware: 4 on Windows, 1 elsewhere.

Signed-off-by: Sebastien Tardif <sebtardif@ncf.ca>

Author: SebTardif

test/unit/binaryDiscovery.test.ts

@@ -79,7 +79,11 @@ test("findOnPath deduplicates PATH entries", async () => {
     });
 
     assert.equal(found, fakeBinary);
-    assert.equal(checkCount, 1, "should only check each directory once");
+    // On Windows, findOnPath checks 4 candidate names per directory
+    // (patchloom.exe, .cmd, .bat, patchloom); on Unix just 1.
+    // Dedup reduces 3 identical dirs to 1, so: 4 checks (win) or 1 (unix).
+    const expectedChecks = process.platform === "win32" ? 4 : 1;
+    assert.equal(checkCount, expectedChecks, "should only check each directory once");
   });
 });