Fix remaining Windows Unicode issue in test output checker

- Added platform detection to check_outputs.py
- Use ASCII characters ([OK], [FAIL]) on Windows
- Keep Unicode characters (✓, ✗) on Unix-like systems
- Fixes the last failing test on Windows CI

Author: jeremymanning

tests/check_outputs.py

@@ -2,6 +2,7 @@
 """Check that expected output files were generated."""
 
 import sys
+import platform
 from pathlib import Path
 
 output_dir = Path('tests/output_all')
@@ -14,11 +15,23 @@
         print(f'  - {f.name}: {size_kb:.1f} KB')
 
     if len(files) >= 5:
-        print(f'\n✓ All expected files generated successfully!')
+        # Use ASCII characters on Windows to avoid encoding issues
+        if platform.system() == 'Windows':
+            print(f'\n[OK] All expected files generated successfully!')
+        else:
+            print(f'\n✓ All expected files generated successfully!')
         sys.exit(0)
     else:
-        print(f'\n✗ Expected at least 5 PDFs, found {len(files)}')
+        # Use ASCII characters on Windows to avoid encoding issues
+        if platform.system() == 'Windows':
+            print(f'\n[FAIL] Expected at least 5 PDFs, found {len(files)}')
+        else:
+            print(f'\n✗ Expected at least 5 PDFs, found {len(files)}')
         sys.exit(1)
 else:
-    print('✗ Output directory not found')
+    # Use ASCII characters on Windows to avoid encoding issues
+    if platform.system() == 'Windows':
+        print('[FAIL] Output directory not found')
+    else:
+        print('✗ Output directory not found')
     sys.exit(1)