feat(mail): 增强邮件规则与阅读体验

- 将收件规则升级为支持多条件、多动作、应用现有邮件和终止继续处理。
- 新增规则构建与显示模式设置，优化规则列表与邮件详情展示。
- 增加邮件列表简洁模式、批量操作、手动刷新和更精细的已读状态控制。

apps/web/src/lib/display-mode.ts

@@ -0,0 +1,36 @@
+import * as React from "react"
+
+export type DisplayMode = "detailed" | "compact"
+
+const DISPLAY_MODE_KEY = "lanqin:display-mode"
+
+export function getInitialDisplayMode(): DisplayMode {
+  if (typeof window === "undefined") return "detailed"
+  return window.localStorage.getItem(DISPLAY_MODE_KEY) === "compact" ? "compact" : "detailed"
+}
+
+export function setStoredDisplayMode(mode: DisplayMode) {
+  window.localStorage.setItem(DISPLAY_MODE_KEY, mode)
+  window.dispatchEvent(new CustomEvent("lanqin:display-mode", { detail: mode }))
+}
+
+export function useDisplayMode() {
+  const [displayMode, setDisplayModeState] = React.useState<DisplayMode>(getInitialDisplayMode)
+  React.useEffect(() => {
+    function sync() {
+      setDisplayModeState(getInitialDisplayMode())
+    }
+    window.addEventListener("storage", sync)
+    window.addEventListener("lanqin:display-mode", sync)
+    return () => {
+      window.removeEventListener("storage", sync)
+      window.removeEventListener("lanqin:display-mode", sync)
+    }
+  }, [])
+  const setDisplayMode = React.useCallback((mode: DisplayMode) => {
+    setStoredDisplayMode(mode)
+    setDisplayModeState(mode)
+  }, [])
+  return [displayMode, setDisplayMode] as const
+}
+