素材图片在高分辨率屏幕上清晰显示；项目资源对话框点整行勾选

- 素材库每张图另外渲染一份两倍尺寸（name.2x.png），build-gallery.sh 把图片编号（原尺寸 PNG 的
  SHA-1，和运行器给图片的编号相同）和两倍图写进 index.json
- 网页认出素材图片（按编号或素材网址），图片框用 srcset、背景用 image-set，系统缩放 150%、200%
  的屏幕上不再发虚；学生程序读到的仍是原尺寸图片，宽高、评分都不变
- 素材清单 index.json 每次向服务器确认（不再缓存一小时），部署新素材后立即生效
- 项目资源对话框：点整行就能勾选（原来只能点复选框，"试听"不会勾选）；缩略图用灰色棋盘格底，
  透明背景上的白色图片（ico_title）也看得见

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

runtime/Sim.WinForms/Resources/README.md

@@ -2,6 +2,6 @@
 
 学生在"项目资源"里添加的图片和声音（`Properties.Resources.xxx`），名字和尺寸与教材一致，全部由平台自绘或合成（不使用教材配套资料里的素材）。
 
-- `gallery/`：发布给运行器和网页的文件，`index.json` 是清单（名字、文件、中文说明、类型）。
+- `gallery/`：发布给运行器和网页的文件，`index.json` 是清单（名字、文件、中文说明、类型；图片还有编号 key 和两倍图 hidpi，由 `build-gallery.sh` 写入）。`name.png` 是原尺寸，学生程序读到的就是它；`name.2x.png` 只给高分辨率屏幕的浏览器显示用，宽高仍按原尺寸。
 - `svg/`：图片的源文件；`project8.py` 生成项目 8 的那些 SVG。改了以后运行 `python3 project8.py && sh build-gallery.sh` 重新生成 PNG（需要 rsvg-convert 和思源黑体）。
 - `gallery/ring.mp3`：用 ffmpeg 合成的门铃声（叮—咚），命令见提交记录。

runtime/Sim.WinForms/Resources/build-gallery.sh

@@ -1,6 +1,23 @@
 #!/bin/sh
-# 把 svg/ 下的素材渲染成 gallery/ 下的 PNG（尺寸取 SVG 自己的 width / height）。需要 rsvg-convert 和思源黑体等中文字体。
+# 把 svg/ 下的素材渲染成 gallery/ 下的 PNG：name.png 是原尺寸（学生程序读到的图片，宽高和教材一致），
+# name.2x.png 是两倍尺寸（只给高分辨率屏幕的浏览器显示用）。然后把每张图的编号（原尺寸 PNG 的 SHA-1，
+# 和运行器给图片的编号相同）和两倍图的文件名写进 gallery/index.json。需要 rsvg-convert 和思源黑体等中文字体。
 cd "$(dirname "$0")"
 for f in svg/*.svg; do
-  rsvg-convert "$f" -o "gallery/$(basename "$f" .svg).png"
+  name=$(basename "$f" .svg)
+  rsvg-convert "$f" -o "gallery/$name.png"
+  rsvg-convert -z 2 "$f" -o "gallery/$name.2x.png"
 done
+python3 - <<'PY'
+import hashlib, json, os
+items = json.load(open("gallery/index.json", encoding="utf-8"))
+for item in items:
+    if item["kind"] != "image":
+        continue
+    item["key"] = hashlib.sha1(open(f"gallery/{item['file']}", "rb").read()).hexdigest()
+    hidpi = item["file"].replace(".png", ".2x.png")
+    if os.path.exists(f"gallery/{hidpi}"):
+        item["hidpi"] = hidpi
+lines = ",\n".join("  " + json.dumps(i, ensure_ascii=False) for i in items)
+open("gallery/index.json", "w", encoding="utf-8").write(f"[\n{lines}\n]\n")
+PY

runtime/Sim.WinForms/Resources/gallery/index.json

@@ -1,27 +1,27 @@
 [
-  { "name": "switch_on", "file": "switch_on.png", "label": "开关：开", "kind": "image" },
-  { "name": "switch_off", "file": "switch_off.png", "label": "开关：关", "kind": "image" },
-  { "name": "ring", "file": "ring.mp3", "label": "铃声", "kind": "audio" },
-  { "name": "ico_title", "file": "ico_title.png", "label": "标题：智慧校园", "kind": "image" },
-  { "name": "bg_home", "file": "bg_home.png", "label": "主界面背景：校园", "kind": "image" },
-  { "name": "icon_02", "file": "icon_02.png", "label": "图标：校园环境", "kind": "image" },
-  { "name": "icon_03", "file": "icon_03.png", "label": "图标：校园安防", "kind": "image" },
-  { "name": "icon_04", "file": "icon_04.png", "label": "图标：退出", "kind": "image" },
-  { "name": "day_01", "file": "day_01.png", "label": "路灯场景：亮灯", "kind": "image" },
-  { "name": "day_02", "file": "day_02.png", "label": "路灯场景：灭灯", "kind": "image" },
-  { "name": "bg_from1", "file": "bg_from1.png", "label": "面板背景（宽）", "kind": "image" },
-  { "name": "bg_from2", "file": "bg_from2.png", "label": "面板背景（窄）", "kind": "image" },
-  { "name": "icon_monitor", "file": "icon_monitor.png", "label": "监控：无画面", "kind": "image" },
-  { "name": "panel_video_ctrl", "file": "panel_video_ctrl.png", "label": "监控：方向盘底座", "kind": "image" },
-  { "name": "btn_arrow_up_normal", "file": "btn_arrow_up_normal.png", "label": "方向键：上", "kind": "image" },
-  { "name": "btn_arrow_up_press", "file": "btn_arrow_up_press.png", "label": "方向键：上（按下）", "kind": "image" },
-  { "name": "btn_arrow_down_normal", "file": "btn_arrow_down_normal.png", "label": "方向键：下", "kind": "image" },
-  { "name": "btn_arrow_down_press", "file": "btn_arrow_down_press.png", "label": "方向键：下（按下）", "kind": "image" },
-  { "name": "btn_arrow_left_normal", "file": "btn_arrow_left_normal.png", "label": "方向键：左", "kind": "image" },
-  { "name": "btn_arrow_left_press", "file": "btn_arrow_left_press.png", "label": "方向键：左（按下）", "kind": "image" },
-  { "name": "btn_arrow_right_normal", "file": "btn_arrow_right_normal.png", "label": "方向键：右", "kind": "image" },
-  { "name": "btn_arrow_right_press", "file": "btn_arrow_right_press.png", "label": "方向键：右（按下）", "kind": "image" },
-  { "name": "arrow_left_normal", "file": "arrow_left_normal.png", "label": "翻页：上一张", "kind": "image" },
-  { "name": "arrow_right_normal", "file": "arrow_right_normal.png", "label": "翻页：下一张", "kind": "image" },
-  { "name": "windowstate_closed_hover", "file": "windowstate_closed_hover.png", "label": "关闭按钮", "kind": "image" }
+  {"name": "switch_on", "file": "switch_on.png", "label": "开关：开", "kind": "image", "key": "6e660e1ff6fc2ff3167919bc386c300112bbce72", "hidpi": "switch_on.2x.png"},
+  {"name": "switch_off", "file": "switch_off.png", "label": "开关：关", "kind": "image", "key": "5d748b614084e878d6189d22f27813477cb8f4d9", "hidpi": "switch_off.2x.png"},
+  {"name": "ring", "file": "ring.mp3", "label": "铃声", "kind": "audio"},
+  {"name": "ico_title", "file": "ico_title.png", "label": "标题：智慧校园", "kind": "image", "key": "8a4db5ad7bc26136ae48056d6e71fa077e36e80f", "hidpi": "ico_title.2x.png"},
+  {"name": "bg_home", "file": "bg_home.png", "label": "主界面背景：校园", "kind": "image", "key": "e56bcc13f7128dec305b6012b255d63fb0f94450", "hidpi": "bg_home.2x.png"},
+  {"name": "icon_02", "file": "icon_02.png", "label": "图标：校园环境", "kind": "image", "key": "fa6a1eaa87c87913803c77f928fa9c16b7f4bf6d", "hidpi": "icon_02.2x.png"},
+  {"name": "icon_03", "file": "icon_03.png", "label": "图标：校园安防", "kind": "image", "key": "d085064a505544968278a85233b7d9ac23661169", "hidpi": "icon_03.2x.png"},
+  {"name": "icon_04", "file": "icon_04.png", "label": "图标：退出", "kind": "image", "key": "c853d74ecab64a9ee85bdf24ccfa63e80123cce3", "hidpi": "icon_04.2x.png"},
+  {"name": "day_01", "file": "day_01.png", "label": "路灯场景：亮灯", "kind": "image", "key": "05065abdb4538906bd7c86e940ab5fb02d51469d", "hidpi": "day_01.2x.png"},
+  {"name": "day_02", "file": "day_02.png", "label": "路灯场景：灭灯", "kind": "image", "key": "470d523e90e188fe5c423d8cffeae6993d5528ff", "hidpi": "day_02.2x.png"},
+  {"name": "bg_from1", "file": "bg_from1.png", "label": "面板背景（宽）", "kind": "image", "key": "7a8c0a16fcab37b28a66e041024b25341cc69462", "hidpi": "bg_from1.2x.png"},
+  {"name": "bg_from2", "file": "bg_from2.png", "label": "面板背景（窄）", "kind": "image", "key": "52497df301d2b7e4eac0c297ce2316ef24863c47", "hidpi": "bg_from2.2x.png"},
+  {"name": "icon_monitor", "file": "icon_monitor.png", "label": "监控：无画面", "kind": "image", "key": "23e6f1efc0f382c17d8a091b76531a3b5879349d", "hidpi": "icon_monitor.2x.png"},
+  {"name": "panel_video_ctrl", "file": "panel_video_ctrl.png", "label": "监控：方向盘底座", "kind": "image", "key": "396443a1d8c141942c0f447e0c69786cf6ad3350", "hidpi": "panel_video_ctrl.2x.png"},
+  {"name": "btn_arrow_up_normal", "file": "btn_arrow_up_normal.png", "label": "方向键：上", "kind": "image", "key": "3c8b75ad465c8a61d0279facc233a0c64b62205a", "hidpi": "btn_arrow_up_normal.2x.png"},
+  {"name": "btn_arrow_up_press", "file": "btn_arrow_up_press.png", "label": "方向键：上（按下）", "kind": "image", "key": "51e1b9926d2bd611e3fda74a01231b46a930c460", "hidpi": "btn_arrow_up_press.2x.png"},
+  {"name": "btn_arrow_down_normal", "file": "btn_arrow_down_normal.png", "label": "方向键：下", "kind": "image", "key": "caf46f81c15aaca788462ebc47e58df299f097d9", "hidpi": "btn_arrow_down_normal.2x.png"},
+  {"name": "btn_arrow_down_press", "file": "btn_arrow_down_press.png", "label": "方向键：下（按下）", "kind": "image", "key": "88c1bea8d6fad99b14658d8265a88b04bc595006", "hidpi": "btn_arrow_down_press.2x.png"},
+  {"name": "btn_arrow_left_normal", "file": "btn_arrow_left_normal.png", "label": "方向键：左", "kind": "image", "key": "a38beb2373154d0474ad1715035aec5e2adf8c3f", "hidpi": "btn_arrow_left_normal.2x.png"},
+  {"name": "btn_arrow_left_press", "file": "btn_arrow_left_press.png", "label": "方向键：左（按下）", "kind": "image", "key": "47bd7a8ffc077130a8ceca627383a4647729c638", "hidpi": "btn_arrow_left_press.2x.png"},
+  {"name": "btn_arrow_right_normal", "file": "btn_arrow_right_normal.png", "label": "方向键：右", "kind": "image", "key": "e69e459f54d67e2c52128015bd6cfcf0e800a893", "hidpi": "btn_arrow_right_normal.2x.png"},
+  {"name": "btn_arrow_right_press", "file": "btn_arrow_right_press.png", "label": "方向键：右（按下）", "kind": "image", "key": "afb1f5fe5a14b7cef298a7d4c67c4cece9e01170", "hidpi": "btn_arrow_right_press.2x.png"},
+  {"name": "arrow_left_normal", "file": "arrow_left_normal.png", "label": "翻页：上一张", "kind": "image", "key": "5a9036955f791f0c41ba52afffb5ecc640d137f1", "hidpi": "arrow_left_normal.2x.png"},
+  {"name": "arrow_right_normal", "file": "arrow_right_normal.png", "label": "翻页：下一张", "kind": "image", "key": "62c53dfb3acf291ef07d6e52fcb989cd48c020b9", "hidpi": "arrow_right_normal.2x.png"},
+  {"name": "windowstate_closed_hover", "file": "windowstate_closed_hover.png", "label": "关闭按钮", "kind": "image", "key": "e361965dbd881dc21511208ce11f649517e8ddb6", "hidpi": "windowstate_closed_hover.2x.png"}
 ]