feat: 新增键盘快捷键设置

- 设置页新增「键盘快捷键」分类，可自定义快捷键绑定
- 支持快速滚动（Home/End/PageUp/PageDown）与导航跳转（Ctrl/Cmd+数字）
- 快捷键绑定与开关按动作独立持久化，默认关闭
- 新增 ui 包 keybinding 组件与工具（KeybindingModal/KeybindingChips 等）

apps/app-frontend/src/composables/useKeyboardShortcuts.ts

@@ -0,0 +1,215 @@
+import {
+	type KeyBinding,
+	bindingMatchesKeyboardEvent,
+	bindingMatchesMouseEvent,
+	bindingMatchesWheelEvent,
+	useModalStack,
+} from '@modrinth/ui'
+import { computed, onUnmounted } from 'vue'
+import { useRoute, useRouter } from 'vue-router'
+
+import { useNetworkStatus } from '@/composables/useNetworkStatus'
+import {
+	SCROLL_ACTIONS,
+	SHORTCUT_ACTIONS,
+	type ShortcutAction,
+} from '@/helpers/shortcut-actions'
+import { resolveAllBindings } from '@/helpers/shortcut-bindings'
+import { getNavShortcutEnabled } from '@/helpers/nav-shortcut-state'
+import { getQuickScrollEnabled } from '@/helpers/scroll-top-state'
+import { useTheming } from '@/store/theme'
+
+/** Editing surfaces keep these keys for themselves. */
+function isEditableTarget(target: EventTarget | null) {
+	return (
+		target instanceof HTMLInputElement ||
+		target instanceof HTMLTextAreaElement ||
+		target instanceof HTMLSelectElement ||
+		(target instanceof HTMLElement && target.isContentEditable)
+	)
+}
+
+function scrollsAtOwnLevel(element: Element) {
+	const { overflowY } = getComputedStyle(element)
+	return /(auto|scroll|overlay)/.test(overflowY) && element.scrollHeight > element.clientHeight
+}
+
+/** A container that scrolls the page itself rather than a widget on it. */
+function isPageScroller(element: Element) {
+	return scrollsAtOwnLevel(element) && element.clientHeight >= window.innerHeight / 2
+}
+
+/** Nearest scrolling ancestor, whatever its size. */
+function nearestScrollContainer(target: EventTarget | null) {
+	let element = target instanceof Element ? target : null
+	while (element) {
+		if (scrollsAtOwnLevel(element)) return element
+		element = element.parentElement
+	}
+	return null
+}
+
+/**
+ * The page's own scroller. Most pages scroll inside `.app-viewport`, but some
+ * screens (settings, consoles, studios) turn that element's scrolling off and
+ * host a full-height container inside it, so fall back to whatever fills the
+ * middle of the viewport.
+ */
+function resolvePageScroller() {
+	const viewport = document.querySelector<HTMLElement>('.app-viewport')
+	if (!viewport) return null
+	if (isPageScroller(viewport)) return viewport
+
+	const bounds = viewport.getBoundingClientRect()
+	let element: Element | null = document.elementFromPoint(
+		bounds.left + bounds.width / 2,
+		bounds.top + bounds.height / 2,
+	)
+	while (element) {
+		if (isPageScroller(element)) return element
+		element = element.parentElement
+	}
+
+	return viewport
+}
+
+export function setupKeyboardShortcuts() {
+	const themeStore = useTheming()
+	const { hasModal } = useModalStack()
+	const route = useRoute()
+	const router = useRouter()
+	const { offline } = useNetworkStatus()
+
+	themeStore.quickScrollEnabled = getQuickScrollEnabled()
+	for (const shortcut of SHORTCUT_ACTIONS) {
+		if (shortcut.group === 'nav') themeStore[shortcut.enabledField] = getNavShortcutEnabled(shortcut.id)
+	}
+	themeStore.shortcutBindings = resolveAllBindings()
+
+	/** The combination an action answers to now: recorded if there is one, default otherwise. */
+	function bindingFor(action: ShortcutAction): KeyBinding {
+		return themeStore.shortcutBindings[action.id] ?? action.defaultBinding
+	}
+
+	/** Whether an action is switched on and reachable in the current state. */
+	function shortcutIsAvailable(action: ShortcutAction): boolean {
+		if (!themeStore[action.enabledField]) return false
+		return !action.unavailable?.({
+			worldsTabEnabled: themeStore.featureFlags.worlds_tab,
+			offline: offline.value,
+		})
+	}
+
+	function findShortcut<E extends Event>(
+		event: E,
+		matches: (binding: KeyBinding, event: E) => boolean,
+		{ includeDisabled = false }: { includeDisabled?: boolean } = {},
+	): ShortcutAction | null {
+		if (hasModal.value) return null
+		if (isEditableTarget(event.target)) return null
+
+		for (const action of SHORTCUT_ACTIONS) {
+			if (!includeDisabled && !shortcutIsAvailable(action)) continue
+			if (matches(bindingFor(action), event)) return action
+		}
+
+		return null
+	}
+
+	/** Does what an action is for. Scrolling actions move the page's own scroller. */
+	function runShortcut(action: ShortcutAction, event: Event) {
+		if (action.target) {
+			router.push(action.target(route))
+			return
+		}
+
+		const focusedContainer = nearestScrollContainer(event.target)
+		if (focusedContainer && !isPageScroller(focusedContainer)) return
+
+		const scroller = resolvePageScroller()
+		if (!scroller) return
+
+		action.applyScroll?.(scroller)
+	}
+
+	function handleScrollShortcutKey(event: KeyboardEvent) {
+		if (event.isComposing) return
+
+		const match = findShortcut(event, bindingMatchesKeyboardEvent, { includeDisabled: true })
+		if (match?.group !== 'scroll') return
+
+		const focusedContainer = nearestScrollContainer(event.target)
+		if (focusedContainer && !isPageScroller(focusedContainer)) return
+
+		const scroller = resolvePageScroller()
+		if (!scroller) return
+
+		event.preventDefault()
+		if (!shortcutIsAvailable(match)) return
+
+		match.applyScroll?.(scroller)
+	}
+
+	function handleNavShortcutKey(event: KeyboardEvent) {
+		if (event.isComposing) return
+
+		const match = findShortcut(event, bindingMatchesKeyboardEvent)
+		if (match?.group !== 'nav') return
+
+		event.preventDefault()
+		runShortcut(match, event)
+	}
+
+	const hasPointerBindings = computed(() =>
+		SHORTCUT_ACTIONS.some((action) => bindingFor(action).device === 'mouse'),
+	)
+
+	function handleShortcutMouse(event: MouseEvent) {
+		if (!hasPointerBindings.value) return
+
+		const match = findShortcut(event, bindingMatchesMouseEvent)
+		if (!match) return
+
+		event.preventDefault()
+		event.stopPropagation()
+		runShortcut(match, event)
+	}
+
+	function handleShortcutWheel(event: WheelEvent) {
+		if (!hasPointerBindings.value) return
+
+		const match = findShortcut(event, bindingMatchesWheelEvent)
+		if (!match) return
+
+		event.preventDefault()
+		event.stopPropagation()
+		runShortcut(match, event)
+	}
+
+	function handleGlobalKeydown(event: KeyboardEvent) {
+		const key = event.key.toLowerCase()
+		const isFindShortcut = key === 'f' && (event.ctrlKey || event.metaKey)
+		const isBlockedDevtoolsShortcut = event.key === 'F12' && !themeStore.devMode
+
+		if (isFindShortcut || isBlockedDevtoolsShortcut) {
+			event.preventDefault()
+			event.stopPropagation()
+		}
+
+		handleScrollShortcutKey(event)
+		handleNavShortcutKey(event)
+	}
+
+	window.addEventListener('keydown', handleGlobalKeydown, true)
+	window.addEventListener('mousedown', handleShortcutMouse, true)
+	// Not passive: a bound wheel direction has to keep the page from scrolling.
+	window.addEventListener('wheel', handleShortcutWheel, { capture: true, passive: false })
+
+	onUnmounted(() => {
+		window.removeEventListener('keydown', handleGlobalKeydown, true)
+		window.removeEventListener('mousedown', handleShortcutMouse, true)
+		window.removeEventListener('wheel', handleShortcutWheel, { capture: true, passive: false })
+	})
+
+	return { bindingFor, shortcutIsAvailable, SCROLL_ACTIONS }
+}