fix: resolve Windows Unicode encoding errors in CI workflow verification scripts

 **Unicode Encoding Fixes:**
- Replace Unicode emojis with ASCII alternatives in CI verification scripts to prevent Windows console encoding errors
- Add PYTHONIOENCODING=utf-8 environment variable to all Python steps for proper Unicode handling
- Fix UnicodeEncodeError: 'charmap' codec can't encode character '\u2705' on Windows Server

 **Specific Changes:**
1. Build Python extension verification script:
   - Replace  (U+2705) with [OK] for success messages
   - Replace  (U+274C) with [ERROR] for error messages
   - Replace  (U+26A0) with [WARN] for warning messages

2. Fallback test verification:
   - Replace  with [OK] in success message

3. Environment variable additions:
   - Add PYTHONIOENCODING=utf-8 to Build Python extension step
   - Add PYTHONIOENCODING=utf-8 to Run Python tests step
   - Add PYTHONIOENCODING=utf-8 to Test pure Python fallback step
   - Add PYTHONIOENCODING=utf-8 to Run integration tests step

 **Cross-Platform Compatibility:**
- ASCII alternatives work on all platforms (Ubuntu, Windows, macOS)
- UTF-8 encoding ensures Unicode characters in integration tests display correctly
- Maintains clear status reporting while preventing encoding errors
- Preserves all verification functionality

 **Verification:**
- Local testing confirms ASCII alternatives work correctly on Windows
- UTF-8 encoding allows integration test script to run without Unicode errors
- All verification scripts maintain same functionality with improved compatibility

**Root Cause:** Windows console uses cp1252 encoding by default, which cannot display Unicode emoji characters ( U+2705,  U+274C,  U+26A0) used in verification scripts.

**Solution:** Dual approach - ASCII alternatives for inline scripts + UTF-8 encoding environment variable for external scripts that use Unicode characters.

Author: jj-devhub

.github/workflows/ci.yml

@@ -171,6 +171,8 @@ jobs:
 
     - name: Build Python extension
       shell: bash
+      env:
+        PYTHONIOENCODING: utf-8
       run: |
         source venv/bin/activate || source venv/Scripts/activate
         echo "Building Rust extension with maturin..."
@@ -180,29 +182,33 @@ jobs:
         python -c "
         try:
             import demopy
-            print('✅ Successfully imported demopy')
+            print('[OK] Successfully imported demopy')
             print(f'Version: {demopy.__version__}')
             hello_result = demopy.hello()
             print(f'Hello: {hello_result}')
             if 'Rust edition' in hello_result:
-                print('✅ Using Rust extension')
+                print('[OK] Using Rust extension')
             elif 'Python fallback' in hello_result:
-                print('✅ Using Python fallback')
+                print('[OK] Using Python fallback')
             else:
-                print(f'⚠️  Unknown implementation: {hello_result}')
+                print(f'[WARN] Unknown implementation: {hello_result}')
         except Exception as e:
-            print(f'❌ Import failed: {e}')
+            print(f'[ERROR] Import failed: {e}')
             raise
         "
 
     - name: Run Python tests
       shell: bash
+      env:
+        PYTHONIOENCODING: utf-8
       run: |
         source venv/bin/activate || source venv/Scripts/activate
         pytest tests/ -v
     
     - name: Test pure Python fallback
       shell: bash
+      env:
+        PYTHONIOENCODING: utf-8
       run: |
         source venv/bin/activate || source venv/Scripts/activate
         # Test that fallback works when Rust extension is not available
@@ -227,11 +233,13 @@ jobs:
         assert demopy.sum_list([1, 2, 3]) == 6
         assert demopy.reverse_string('hello') == 'olleh'
         assert demopy.power(2, 3) == 8
-        print('✅ Pure Python fallback test passed!')
+        print('[OK] Pure Python fallback test passed!')
         "
 
     - name: Run integration tests
       shell: bash
+      env:
+        PYTHONIOENCODING: utf-8
       run: |
         source venv/bin/activate || source venv/Scripts/activate
         python scripts/test_integration.py