fix(build): preserve the existing installer icon

scripts/create_installer.py

@@ -87,12 +87,12 @@ def create_installer():
 
     print("\n[1/3] Preparing installer files...")
 
-    # Convert tray_ready.png to ICO format for installer
+    # Preserve the tracked ICO; convert the PNG only when the ICO is missing.
     # Inno Setup requires ICO format for SetupIconFile
     png_icon = ROOT / "assets/tray_ready.png"
     ico_icon = ROOT / "assets/icon.ico"
 
-    if png_icon.exists() and PIL_AVAILABLE:
+    if not ico_icon.exists() and png_icon.exists() and PIL_AVAILABLE:
         try:
             # Convert PNG to ICO with multiple sizes for best compatibility
             with Image.open(png_icon) as img:

test/test_create_installer_icon.py

@@ -0,0 +1,78 @@
+import contextlib
+import importlib.util
+import io
+import tempfile
+import unittest
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import Mock, patch
+
+
+SPEC = importlib.util.spec_from_file_location('rose_installer_icon_test', Path(__file__).resolve().parents[1] / 'scripts/create_installer.py')
+builder = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(builder)
+
+
+class InstallerIconTests(unittest.TestCase):
+    def setUp(self):
+        temporary = tempfile.TemporaryDirectory()
+        self.addCleanup(temporary.cleanup)
+        self.root = Path(temporary.name)
+        self.home = self.root / 'home'
+        compiler = self.home / 'AppData/Local/Programs/Inno Setup 6/ISCC.exe'
+        compiler.parent.mkdir(parents=True)
+        compiler.touch()
+        (self.root / 'assets').mkdir()
+        (self.root / 'dist/Rose').mkdir(parents=True)
+        (self.root / 'installer.iss').write_text('stub')
+        self.icon = self.root / 'assets/icon.ico'
+        self.png = self.root / 'assets/tray_ready.png'
+        self.png.write_bytes(b'png input')
+
+    def build(self, image, pil_available=True):
+        def compile_installer(*args, **kwargs):
+            (self.root / 'installer/Rose_Setup_1.exe').write_bytes(b'fake installer')
+            return SimpleNamespace(returncode=0)
+
+        with patch.object(builder, 'ROOT', self.root), patch.object(Path, 'home', return_value=self.home), \
+                patch.object(builder, 'PIL_AVAILABLE', pil_available), \
+                patch.object(builder, 'Image', image, create=True), \
+                patch.object(builder.subprocess, 'run', side_effect=compile_installer) as compiler, \
+                contextlib.redirect_stdout(io.StringIO()):
+            result = builder.create_installer()
+        return result, compiler
+
+    def test_existing_icon_bytes_are_preserved_and_copied_without_conversion(self):
+        self.icon.write_bytes(b'original tracked ico')
+        image = Mock()
+        image.open.return_value.__enter__ = Mock(return_value=SimpleNamespace(
+            save=lambda path, **kwargs: path.write_bytes(b'regenerated icon')))
+        image.open.return_value.__exit__ = Mock(return_value=False)
+        result, compiler = self.build(image)
+        self.assertTrue(result)
+        image.open.assert_not_called()
+        self.assertEqual(self.icon.read_bytes(), b'original tracked ico')
+        self.assertEqual((self.root / 'dist/Rose/icon.ico').read_bytes(), b'original tracked ico')
+        compiler.assert_called_once()
+
+    def test_missing_icon_is_generated_from_png_and_copied(self):
+        image = Mock()
+        image.open.return_value.__enter__ = Mock(return_value=SimpleNamespace(
+            save=lambda path, **kwargs: path.write_bytes(b'generated ico')))
+        image.open.return_value.__exit__ = Mock(return_value=False)
+        result, compiler = self.build(image)
+        self.assertTrue(result)
+        self.assertEqual(self.icon.read_bytes(), b'generated ico')
+        self.assertEqual((self.root / 'dist/Rose/icon.ico').read_bytes(), b'generated ico')
+        compiler.assert_called_once()
+
+    def test_conversion_failure_without_an_icon_does_not_compile(self):
+        image = Mock()
+        image.open.side_effect = OSError('bad PNG')
+        result, compiler = self.build(image)
+        self.assertFalse(result)
+        compiler.assert_not_called()
+
+    def test_existing_icon_works_without_pillow(self):
+        self.icon.write_bytes(b'original ico')
+        self.assertTrue(self.build(Mock(), pil_available=False)[0])