fix(workspace): sort daily memory by date and inline into file grid

- Sort daily memory list by filename (YYYY-MM-DD.md) instead of mtime
  so editing an older file no longer bumps it to the top
- Move daily memory card inline with workspace MD file buttons
- Shorten card description across all locales
- Defer file creation until user actually saves (no empty file on create)

src/i18n/locales/en.json

@@ -1171,7 +1171,7 @@
       "title": "Daily Memory",
       "sectionTitle": "Daily Memory",
       "cardTitle": "Daily Memory Files",
-      "cardDescription": "Browse and manage daily memory notes (memory/YYYY-MM-DD.md)",
+      "cardDescription": "Browse & manage daily memories",
       "createToday": "Today's Note",
       "empty": "No daily memory files yet",
       "loadFailed": "Failed to load daily memory files",

src/i18n/locales/ja.json

@@ -1171,7 +1171,7 @@
       "title": "デイリーメモリー",
       "sectionTitle": "デイリーメモリー",
       "cardTitle": "デイリーメモリーファイル",
-      "cardDescription": "デイリーメモリーノートの閲覧と管理（memory/YYYY-MM-DD.md）",
+      "cardDescription": "デイリーメモリーの閲覧・管理",
       "createToday": "今日のノート",
       "empty": "デイリーメモリーファイルはまだありません",
       "loadFailed": "デイリーメモリーファイルの読み込みに失敗しました",

src/i18n/locales/zh.json

@@ -1171,7 +1171,7 @@
       "title": "每日记忆",
       "sectionTitle": "每日记忆",
       "cardTitle": "每日记忆文件",
-      "cardDescription": "浏览和管理每日记忆笔记（memory/YYYY-MM-DD.md）",
+      "cardDescription": "浏览管理每日记忆",
       "createToday": "今日笔记",
       "empty": "暂无每日记忆文件",
       "loadFailed": "加载每日记忆文件失败",