Refactor BottomNav to use localized labels for navigation items; added support for dynamic language selection based on device state. Updated locale files for English, Traditional Chinese, and Simplified Chinese to include bottom navigation labels.

client/src/locales/data-en.json

@@ -1,6 +1,7 @@
 {
   "home": {
     "audioSet": "Audio setting",
+    "systemSet": "System",
     "power": "Power",
     "input": "Input",
     "output": "Output",
@@ -12,6 +13,16 @@
     "powerOffToastDemo": "Demo mode: disconnected from the device.",
     "powerOffToastSent": "Shutdown command sent."
   },
+  "vuPage": {
+    "title": "VU meter gallery"
+  },
+  "bottomNav": {
+    "community": "Community",
+    "hpEq": "HP-EQ",
+    "home": "Home",
+    "effects": "Effects",
+    "myAi": "My AI"
+  },
   "source": {
     "label": "Input/Output",
     "input": {
@@ -134,7 +145,7 @@
     "Standard": "Standard equalizer preset",
     "edit": "Batch Edit",
     "headset": "Add HeadSet",
-    "preamp": "Preamp",
+    "preamp": "Total gain",
     "filters": {
       "label": "Filters",
       "options": [
@@ -203,7 +214,57 @@
     "gain": "GAIN",
     "q": "Q value",
     "loadDeviceBtn": "confirm",
-    "peqNoneItem": "Unconfigured"
+    "peqNoneItem": "Unconfigured",
+    "eqUi": {
+      "batchEditTitle": "Batch edit",
+      "batchEditHint": "11 lines total: line 1 is Preamp, lines 2–11 are Filter 1–10. Saving overwrites the current headphone preset.",
+      "cancel": "Cancel",
+      "save": "Save",
+      "tabBrands": "Brands",
+      "tabModels": "Models",
+      "tabTarget": "Target",
+      "searchPlaceholder": "Search brand or model",
+      "searching": "Searching…",
+      "noSearchResults": "No matching brand or model",
+      "loading": "Loading…",
+      "noBrandMatch": "No matching brands",
+      "selectBrandFirst": "Choose a brand on the Brands tab first",
+      "brandLabel": "Brand:",
+      "modelFromSearchLabel": "Model from search:",
+      "noModelsForBrand": "No models for this brand",
+      "targetBrand": "Brand:",
+      "targetModel": "Model:",
+      "targetForm": "Form:",
+      "formAll": "All",
+      "confirmLoading": "Working…",
+      "confirmButton": "Confirm",
+      "selectModelFirst": "Select a model first",
+      "noTargets": "No target curves available",
+      "closeDrawer": "Close",
+      "toastBatchApplied": "Batch edit applied",
+      "toastBatchParseError": "Invalid batch edit format",
+      "toastBrandsFail": "Failed to load brands",
+      "toastModelsFail": "Failed to load models",
+      "toastCurveFail": "Failed to load curve",
+      "toastNewEqOk": "New headphone EQ saved",
+      "toastTargetSelected": "Target selected: {{name}}",
+      "deleteConfirm": "Delete headphone \"{{name}}\"?",
+      "toastDeleted": "Headphone removed",
+      "toastDeleteFail": "Failed to delete headphone",
+      "bassBoost": "Bass boost: fc {{fc}}, q {{q}}, gain {{gain}} dB",
+      "errMinLines": "At least 11 lines required (Preamp + 10 filters)",
+      "errPreampFirstLine": "Line 1 must look like Preamp:-5.96dB",
+      "errPreampValue": "Invalid Preamp value",
+      "errFilterLine": "Line {{line}} does not match the Filter format",
+      "errFilterNoRange": "Filter number {{no}} is out of range",
+      "errFilterType": "Invalid type for filter {{no}} ({{type}})",
+      "errFilterNumbers": "Invalid numbers for filter {{no}}",
+      "errFilterAll": "Filters 1–10 must all be present",
+      "chartCopyTo": "Copy to {{mode}}",
+      "chartLoadToDevice": "Load to device",
+      "toastChartCopied": "Copied to {{mode}}",
+      "toastChartLoadedDevice": "Loaded to device"
+    }
   },
   "dac": {
     "balance": "Left-right balance",