fix: windows icon

Author: radioactiveorange

CLAUDE.md

@@ -22,7 +22,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 - Manual build (Windows): `pyinstaller --noconfirm --onefile --windowed --icon=app_icon.ico --name=glimpse main.py`
 - Manual build (Linux/macOS): `pyinstaller --noconfirm --onefile --windowed --icon=app_icon.png --name=glimpse main.py`
 - Output binary will be in the `dist/` folder
-- **Cross-platform icons**: Spec file bundles both PNG and ICO, runtime selects appropriate format
+- **Cross-platform icons**: Spec file bundles both PNG and ICO, build-time selects appropriate format
 
 ## Architecture
 

glimpse.spec

@@ -1,5 +1,12 @@
 # -*- mode: python ; coding: utf-8 -*-
 
+import sys
+
+# Select appropriate icon format for platform
+if sys.platform.startswith('win'):
+    icon_file = 'app_icon.ico'
+else:
+    icon_file = 'app_icon.png'
 
 a = Analysis(
     ['main.py'],
@@ -35,5 +42,5 @@ exe = EXE(
     target_arch=None,
     codesign_identity=None,
     entitlements_file=None,
-    icon='app_icon.png',
+    icon=icon_file,
 )