feat(hid): 添加 Linux 键盘与 SysRq 快捷键 (#307)

控制台增加独立快捷键菜单，提供常用组合键和 Linux SysRq 指令，虚拟键盘补充 Linux 布局。
通过可靠且有序的 WebSocket 发送组合键，取消或失败时逐一释放按键，防止修饰键残留。
执行期间避免物理键盘与虚拟键盘交错输入，断连、失焦和切换布局时停止执行。
修正焦点移动后的物理按键释放，并将原虚拟键盘组合键迁移到统一菜单。

验证：独立暂存快照前端构建通过；6 项快捷键单测及 5 组浏览器测试通过，覆盖组合键序列、失败清理、取消及键盘焦点。

Refs #307

web/src/components/ActionBar.vue

@@ -48,6 +48,8 @@ import HidConfigPopover from '@/components/HidConfigPopover.vue'
 import AudioConfigPopover from '@/components/AudioConfigPopover.vue'
 import MsdDialog from '@/components/MsdDialog.vue'
 import VideoDisplayControls from '@/components/VideoDisplayControls.vue'
+import KeyboardShortcutsPopover from '@/components/KeyboardShortcutsPopover.vue'
+import type { KeyboardShortcut } from '@/lib/keyboardShortcuts'
 import type { ConsoleLayout } from '@/composables/useConsoleLayout'
 
 const { t, locale } = useI18n()
@@ -73,6 +75,9 @@ const props = defineProps<{
   fullscreen?: boolean
   statsOpen?: boolean
   terminalOpen?: boolean
+  shortcutsReady?: boolean
+  shortcutInputBusy?: boolean
+  shortcutBusy?: boolean
 }>()
 const isSidebarLayout = computed(() => props.layout === 'sidebar')
 const isFloatingLayout = computed(() => props.layout === 'floating')
@@ -106,6 +111,8 @@ const emit = defineEmits<{
   (e: 'reset'): void
   (e: 'wol', macAddress: string): void
   (e: 'openTerminal'): void
+  (e: 'executeShortcut', shortcut: KeyboardShortcut): void
+  (e: 'cancelShortcut'): void
 }>()
 
 const pasteOpen = ref(false)
@@ -114,6 +121,7 @@ const videoPopoverOpen = ref(false)
 const hidPopoverOpen = ref(false)
 const audioPopoverOpen = ref(false)
 const msdDialogOpen = ref(false)
+const shortcutsOpen = ref(false)
 
 const mobileAtxOpen = ref(false)
 const mobilePasteOpen = ref(false)
@@ -259,6 +267,7 @@ watch([() => props.layout, floatingCollapsed, minimalDisplayControls], () => {
   hidPopoverOpen.value = false
   audioPopoverOpen.value = false
   msdDialogOpen.value = false
+  shortcutsOpen.value = false
   mobileAtxOpen.value = false
   mobilePasteOpen.value = false
   void observeLayout()
@@ -521,6 +530,16 @@ const hasRightOverflow = computed(() => {
           @toggle-virtual-keyboard="emit('toggleVirtualKeyboard')"
         />
 
+        <KeyboardShortcutsPopover
+          v-model:open="shortcutsOpen"
+          :ready="props.shortcutsReady === true"
+          :input-busy="props.shortcutInputBusy"
+          :busy="props.shortcutBusy"
+          :side="isSidebarLayout ? 'right' : 'bottom'"
+          @execute="emit('executeShortcut', $event)"
+          @cancel="emit('cancelShortcut')"
+        />
+
         <!-- Connection Stats - Adaptive -->
         <div v-if="isVisible('stats')">
           <TooltipProvider>