feat(agent-images): update Debian and add Podman

tests/unit/test_builtin_agent_images.py

@@ -0,0 +1,34 @@
+"""Unit contracts shared by all built-in agent images."""
+
+from __future__ import annotations
+
+import re
+import unittest
+from pathlib import Path
+
+
+_CONTRIB_DIR = Path(__file__).resolve().parents[2] / "bot_bottle/contrib"
+_AGENT_DOCKERFILES = tuple(sorted(_CONTRIB_DIR.glob("*/Dockerfile")))
+
+
+class TestBuiltinAgentImages(unittest.TestCase):
+    def test_all_use_debian_trixie_stable(self):
+        self.assertTrue(_AGENT_DOCKERFILES)
+        for dockerfile in _AGENT_DOCKERFILES:
+            with self.subTest(provider=dockerfile.parent.name):
+                self.assertRegex(
+                    dockerfile.read_text(),
+                    r"(?m)^FROM node:22-trixie-slim\s*$",
+                )
+
+    def test_all_install_podman(self):
+        for dockerfile in _AGENT_DOCKERFILES:
+            with self.subTest(provider=dockerfile.parent.name):
+                self.assertRegex(
+                    dockerfile.read_text(),
+                    re.compile(r"(?m)^\s*podman(?:\s|\\|$)"),
+                )
+
+
+if __name__ == "__main__":
+    unittest.main()