feat: session manger (#867)

* feat: init session manger

* feat: persist selected app to localStorage

- Save app selection when switching providers
- Restore last selected app on page load

* feat: persist current view to localStorage

- Save view selection when switching tabs
- Restore last selected view on page load

* styles: update ui

* feat: Improve macOS Terminal activation and refactor Kitty launch to use  command with user's default shell.

* fix: session view

* feat: toc

* feat: Implement FlexSearch for improved session search functionality.

* feat: Redesign session manager search and filter UI for a more compact and dynamic experience.

* refactor: modularize session manager by extracting components and utility functions into dedicated files.

* feat: Enhance session terminal launching with support for iTerm2, Ghostty, WezTerm, and Alacritty, including UI and custom configuration options.

* feat: Conditionally render terminal selection and resume session buttons only on macOS.

src/hooks/useSessionSearch.ts

@@ -0,0 +1,134 @@
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import FlexSearch from "flexsearch";
+import type { SessionMeta } from "@/types";
+
+// FlexSearch Index 类型
+type FlexSearchIndex = InstanceType<typeof FlexSearch.Index>;
+
+interface UseSessionSearchOptions {
+  sessions: SessionMeta[];
+  providerFilter: string;
+}
+
+interface UseSessionSearchResult {
+  search: (query: string) => SessionMeta[];
+  isIndexing: boolean;
+}
+
+/**
+ * 使用 FlexSearch 实现会话全文搜索
+ * 索引会话元数据（标题、摘要、项目目录等）
+ */
+export function useSessionSearch({
+  sessions,
+  providerFilter,
+}: UseSessionSearchOptions): UseSessionSearchResult {
+  const [isIndexing, setIsIndexing] = useState(false);
+
+  // 会话元数据索引
+  const indexRef = useRef<FlexSearchIndex | null>(null);
+  // 索引 ID 到 session 的映射
+  const sessionByIdxRef = useRef<SessionMeta[]>([]);
+
+  // 初始化索引
+  useEffect(() => {
+    setIsIndexing(true);
+
+    // 创建索引实例
+    // 使用 forward tokenizer 支持中文前缀搜索
+    const index = new FlexSearch.Index({
+      tokenize: "forward",
+      resolution: 9,
+    });
+
+    // 索引所有会话
+    sessions.forEach((session, idx) => {
+      // 索引会话元数据
+      const metaContent = [
+        session.sessionId,
+        session.title,
+        session.summary,
+        session.projectDir,
+        session.sourcePath,
+      ]
+        .filter(Boolean)
+        .join(" ");
+
+      index.add(idx, metaContent);
+    });
+
+    indexRef.current = index;
+    sessionByIdxRef.current = sessions;
+
+    setIsIndexing(false);
+  }, [sessions]);
+
+  // 搜索函数
+  const search = useCallback(
+    (query: string): SessionMeta[] => {
+      const needle = query.trim().toLowerCase();
+
+      // 先按 provider 过滤
+      let filtered = sessions;
+      if (providerFilter !== "all") {
+        filtered = sessions.filter((s) => s.providerId === providerFilter);
+      }
+
+      // 如果没有搜索词，返回按时间排序的结果
+      if (!needle) {
+        return [...filtered].sort((a, b) => {
+          const aTs = a.lastActiveAt ?? a.createdAt ?? 0;
+          const bTs = b.lastActiveAt ?? b.createdAt ?? 0;
+          return bTs - aTs;
+        });
+      }
+
+      const index = indexRef.current;
+
+      if (!index) {
+        // 索引未就绪，使用简单搜索
+        return filtered
+          .filter((session) => {
+            const haystack = [
+              session.sessionId,
+              session.title,
+              session.summary,
+              session.projectDir,
+              session.sourcePath,
+            ]
+              .filter(Boolean)
+              .join(" ")
+              .toLowerCase();
+            return haystack.includes(needle);
+          })
+          .sort((a, b) => {
+            const aTs = a.lastActiveAt ?? a.createdAt ?? 0;
+            const bTs = b.lastActiveAt ?? b.createdAt ?? 0;
+            return bTs - aTs;
+          });
+      }
+
+      // 使用 FlexSearch 搜索
+      const results = index.search(needle, { limit: 100 }) as number[];
+
+      // 转换为 session 并过滤
+      const matchedSessions = results
+        .map((idx) => sessionByIdxRef.current[idx])
+        .filter(
+          (session) =>
+            session &&
+            (providerFilter === "all" || session.providerId === providerFilter)
+        );
+
+      // 按时间排序
+      return matchedSessions.sort((a, b) => {
+        const aTs = a.lastActiveAt ?? a.createdAt ?? 0;
+        const bTs = b.lastActiveAt ?? b.createdAt ?? 0;
+        return bTs - aTs;
+      });
+    },
+    [sessions, providerFilter]
+  );
+
+  return useMemo(() => ({ search, isIndexing }), [search, isIndexing]);
+}