feat: show actionable temperature hint when reading fails (issue #12)

Sources/ProcessBarMonitor/Resources/en.lproj/Localizable.strings

@@ -59,6 +59,9 @@
 "note.temperature.arm64_unavailable" = "Apple Silicon HID sensors were checked for %@, but no valid value was exposed right now.";
 "note.temperature.intel_hint" = "Intel: install osx-cpu-temp or istats to show a real CPU temperature.";
 "note.temperature.no_source" = "No valid CPU temperature source found.";
+"hint.temperature.intel_install" = "Intel Mac: install osx-cpu-temp or istats to show CPU temperature.";
+"hint.temperature.arm64_read_failed" = "Apple Silicon: temperature reading failed. Check System Settings > Privacy & Security.";
+"note.temperature.available" = "Temperature mode: %@. Source: Apple Silicon HID sensors first, helper fallback second.";
 "button.copy_diagnostics" = "Copy Diagnostics";
 "status.diagnostics_copied" = "Diagnostics copied to clipboard.";
 "status.diagnostics_copy_failed" = "Failed to copy diagnostics.";

Sources/ProcessBarMonitor/Resources/zh-Hans.lproj/Localizable.strings

@@ -59,6 +59,9 @@
 "note.temperature.arm64_unavailable" = "已检查 %@ 的 Apple Silicon HID 传感器，但当前未返回有效值。";
 "note.temperature.intel_hint" = "Intel 机型：安装 osx-cpu-temp 或 istats 以显示真实 CPU 温度。";
 "note.temperature.no_source" = "未找到有效的 CPU 温度来源。";
+"hint.temperature.intel_install" = "Intel Mac：安装 osx-cpu-temp 或 istats 即可显示 CPU 温度。";
+"hint.temperature.arm64_read_failed" = "Apple Silicon：温度读取失败。请检查 系统设置 > 隐私与安全性。";
+"note.temperature.available" = "温度模式：%@。来源：优先 Apple Silicon HID 传感器，其次为辅助工具。";
 "button.copy_diagnostics" = "复制诊断信息";
 "status.diagnostics_copied" = "诊断信息已复制到剪贴板。";
 "status.diagnostics_copy_failed" = "复制诊断信息失败。";

Sources/ProcessBarMonitor/SystemMetricsProvider.swift

@@ -37,6 +37,7 @@ actor SystemMetricsProvider {
             thermalState: ProcessInfo.processInfo.thermalState,
             cpuTemperatureC: temperature,
             architectureNote: architectureAndTemperatureNote(temperatureAvailable: temperature != nil, mode: temperatureMode),
+            temperatureHint: temperatureHint(temperatureAvailable: temperature != nil),
             updatedAt: Date()
         )
     }
@@ -203,4 +204,16 @@ actor SystemMetricsProvider {
         return L10n.string("note.temperature.no_source")
         #endif
     }
+
+    /// Returns an actionable hint string when temperature is unavailable, nil when temperature is present.
+    private func temperatureHint(temperatureAvailable: Bool) -> String? {
+        guard !temperatureAvailable else { return nil }
+        #if arch(arm64)
+        return L10n.string("hint.temperature.arm64_read_failed")
+        #elseif arch(x86_64)
+        return L10n.string("hint.temperature.intel_install")
+        #else
+        return nil
+        #endif
+    }
 }

Sources/ProcessBarMonitor/SystemModels.swift

@@ -134,6 +134,9 @@ struct SystemSummary {
     let thermalState: ProcessInfo.ThermalState
     let cpuTemperatureC: Double?
     let architectureNote: String
+    /// Actionable hint shown when temperature is unavailable (nil).
+    /// - Intel without tool: install hint; Apple Silicon read-fail: permission check hint.
+    let temperatureHint: String?
     let updatedAt: Date
 
     var memoryPressurePercent: Double {
@@ -149,6 +152,7 @@ struct SystemSummary {
         thermalState: .nominal,
         cpuTemperatureC: nil,
         architectureNote: "",
+        temperatureHint: nil,
         updatedAt: Date()
     )
 }

Sources/ProcessBarMonitor/Views.swift

@@ -175,6 +175,12 @@ struct MenuBarContentView: View {
                         .font(.caption)
                         .foregroundStyle(.secondary)
                         .lineLimit(2)
+                    if viewModel.summary.cpuTemperatureC == nil, let hint = viewModel.summary.temperatureHint {
+                        Text(hint)
+                            .font(.caption.weight(.medium))
+                            .foregroundStyle(.orange)
+                            .lineLimit(2)
+                    }
                 }
 
                 HStack(spacing: 8) {