fix: Windows icons use square fill, macOS keeps rounded

- Windows .ico and SquareLogo: content fills 100% canvas, no transparency
- macOS .icns and PNG: keep 80.5% rounded rectangle
- Fixes white/grey square background and blur on Windows

scripts/generate-rounded-icon.py

@@ -43,13 +43,12 @@ def create_rounded_rect_mask(size: int, radius: int) -> Image.Image:
     return mask
 
 
-def compose_icon(size: int, source: Image.Image) -> Image.Image:
-    """原图作为整体，缩放至画布 CONTENT_RATIO，居中，裁成圆角矩形"""
+def compose_icon(size: int, source: Image.Image, rounded: bool = True) -> Image.Image:
+    """原图作为整体，缩放至画布 CONTENT_RATIO，居中"""
     canvas = Image.new("RGBA", (size, size), (0, 0, 0, 0))
 
     plate_size = int(size * CONTENT_RATIO)
     plate_offset = (size - plate_size) // 2
-    radius = int(plate_size * CORNER_RATIO)
 
     # 原图等比缩放，短边充满 plate_size
     src_w, src_h = source.size
@@ -63,12 +62,32 @@ def compose_icon(size: int, source: Image.Image) -> Image.Image:
     top = (new_h - plate_size) // 2
     img = resized.crop((left, top, left + plate_size, top + plate_size))
 
-    # 圆角蒙版裁剪
-    mask = create_rounded_rect_mask(plate_size, radius)
-    canvas.paste(img, (plate_offset, plate_offset), mask)
+    if rounded:
+        # 圆角蒙版裁剪（macOS / Linux）
+        radius = int(plate_size * CORNER_RATIO)
+        mask = create_rounded_rect_mask(plate_size, radius)
+        canvas.paste(img, (plate_offset, plate_offset), mask)
+    else:
+        # 正方形填满（Windows 专用）
+        canvas.paste(img, (plate_offset, plate_offset))
     return canvas
 
 
+def compose_icon_windows(size: int, source: Image.Image) -> Image.Image:
+    """Windows 专用：原图填满整个画布 100%，无圆角，无透明边距"""
+    # 原图等比缩放，短边充满画布
+    src_w, src_h = source.size
+    ratio = max(size / src_w, size / src_h)
+    new_w = int(src_w * ratio)
+    new_h = int(src_h * ratio)
+    resized = source.resize((new_w, new_h), Image.LANCZOS)
+
+    # 居中裁剪到画布尺寸
+    left = (new_w - size) // 2
+    top = (new_h - size) // 2
+    return resized.crop((left, top, left + size, top + size))
+
+
 def generate_icns(source: Image.Image, output_path: str):
     """生成 macOS .icns 文件"""
     import tempfile
@@ -79,10 +98,10 @@ def generate_icns(source: Image.Image, output_path: str):
     iconset_dir = tempfile.mkdtemp(suffix=".iconset")
 
     for sz in sizes:
-        img = compose_icon(sz, source)
+        img = compose_icon(sz, source, rounded=True)
         img.save(os.path.join(iconset_dir, f"icon_{sz}x{sz}.png"))
         if sz <= 512:
-            img2x = compose_icon(sz * 2, source)
+            img2x = compose_icon(sz * 2, source, rounded=True)
             img2x.save(os.path.join(iconset_dir, f"icon_{sz}x{sz}@2x.png"))
 
     subprocess.run(
@@ -102,7 +121,8 @@ def generate_ico(source: Image.Image, output_path: str):
     entries = []
 
     for sz in sizes:
-        img = compose_icon(sz, source)
+        # Windows .ico 填满画布，无圆角，无透明边距
+        img = compose_icon_windows(sz, source)
         buf = io.BytesIO()
         img.save(buf, format="PNG")
         data = buf.getvalue()
@@ -137,9 +157,10 @@ def main():
         compose_icon(size, source).save(path)
         print(f"已生成: {filename} ({size}x{size})")
 
+    # Windows Square Logo 填满画布，无圆角，无透明边距
     for filename, size in SQUARE_SIZES:
         path = os.path.join(ICONS_DIR, filename)
-        compose_icon(size, source).save(path)
+        compose_icon_windows(size, source).save(path)
         print(f"已生成: {filename} ({size}x{size})")
 
     generate_icns(source, os.path.join(ICONS_DIR, "icon.icns"))