Enhance DeviceContext and LuxsinAPI to support new PEQ apply functionality; update locale files for English and Chinese to include new UI strings for applying and saving PEQ settings. Refactor AudioPage and EQPage to integrate boot sound management and improve state handling.

client/src/locales/data-zh-HK.json

@@ -219,9 +219,14 @@
       "errFilterNumbers": "Filter {{no}} 的數值無效",
       "errFilterAll": "Filter 1–10 必須全部提供",
       "chartCopyTo": "複製到 {{mode}}",
-      "chartLoadToDevice": "載入至裝置",
+      "chartApplyB": "套用 B",
+      "chartSaveB": "另存 B",
+      "saveBTitle": "另存 B",
       "toastChartCopied": "已複製到 {{mode}}",
-      "toastChartLoadedDevice": "已載入至裝置"
+      "toastApplyBSuccess": "已將 B 曲線套用到 A",
+      "toastApplyBFail": "套用 B 失敗",
+      "toastSaveBOk": "已另存 B 預設",
+      "toastSaveBFail": "另存 B 失敗"
     }
   },
   "dac": {
@@ -250,7 +255,22 @@
       ]
     },
     "volumeStep": "音量級距",
-    "bootVolume": "開機音量",
+    "bootVolume": {
+      "label": "開機音量",
+      "options": [
+        { "index": 0, "label": "預設" },
+        { "index": 1, "label": "-5dB" },
+        { "index": 2, "label": "-10dB" },
+        { "index": 3, "label": "-15dB" },
+        { "index": 4, "label": "-20dB" },
+        { "index": 5, "label": "-25dB" },
+        { "index": 6, "label": "-30dB" },
+        { "index": 7, "label": "-35dB" },
+        { "index": 8, "label": "-40dB" },
+        { "index": 9, "label": "-45dB" },
+        { "index": 10, "label": "-50dB" }
+      ]
+    },
     "xlr": {
       "label": "XLR端子極性",
       "options": [