feat(system): recognize macOS 26 Tahoe in name map

Apple jumped from macOS 15 (Sequoia) to macOS 26 (Tahoe), skipping versions 16-25.
Smoke tests on macOS 26.4.1 reported 'macOS Unknown 26.4.1'. This update adds
macOS 26 to the name map and improves the test to validate both the new mapping
and ensure truly-unknown versions (99) still return 'Unknown'.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: jgamblin

src/macos_maid/system.py

@@ -16,6 +16,7 @@
     13: "Ventura",
     14: "Sonoma",
     15: "Sequoia",
+    26: "Tahoe",
 }
 
 

tests/test_system.py

@@ -75,4 +75,5 @@ def test_macos_name_mapping():
     assert _macos_name((13, 0, 0)) == "Ventura"
     assert _macos_name((14, 0, 0)) == "Sonoma"
     assert _macos_name((15, 0, 0)) == "Sequoia"
-    assert _macos_name((16, 0, 0)) == "Unknown"
+    assert _macos_name((26, 0, 0)) == "Tahoe"
+    assert _macos_name((99, 0, 0)) == "Unknown"