test(workflows): make catalog ZIP fixture deterministic

Pin the workflow ZIP member timestamp so independently generated catalog and download fixtures remain byte-identical across DOS timestamp boundaries. Add a regression using controlled wall-clock values two seconds apart; it fails with the original helper and passes with the fixed timestamp. Production integrity checks and existing negative tests are unchanged.

Validation: targeted workflow catalog and Junie tests: 78 passed; Ruff: passed. Full pytest collection: 9014 before, 9015 after.

Assisted-by: GitHub Copilot (model: GPT-6.1 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: mnriem

tests/specify_cli/workflows/test_catalog_versions.py

@@ -4,6 +4,7 @@
 
 import hashlib
 import io
+import time
 import zipfile
 
 import pytest
@@ -49,10 +50,24 @@ def _archive(version: str, workflow_id: str = "history-wf", requires=None) -> by
         document["requires"] = requires
     output = io.BytesIO()
     with zipfile.ZipFile(output, "w") as archive:
-        archive.writestr("workflow.yml", yaml.safe_dump(document))
+        archive.writestr(
+            zipfile.ZipInfo("workflow.yml", date_time=(2020, 1, 1, 0, 0, 0)),
+            yaml.safe_dump(document),
+        )
     return output.getvalue()
 
 
+def test_archive_is_independent_of_wall_clock(monkeypatch):
+    archives = []
+    for second in (2, 4):
+        wall_clock = time.struct_time((2026, 9, 30, 14, 39, second, 2, 273, -1))
+        monkeypatch.setattr(
+            zipfile.time, "localtime", lambda timestamp=None, value=wall_clock: value
+        )
+        archives.append(_archive("1.0.0", requires={"integrations": ["copilot"]}))
+    assert archives[0] == archives[1]
+
+
 def _entry() -> dict:
     old = _archive("1.0.0", requires={"integrations": ["copilot"]})
     current = _archive("2.0.0")