fix(session-manager): convert blocking sync I/O to async for improved concurrency

Convert session-manager storage layer from synchronous blocking I/O (readdirSync, readFileSync) to non-blocking async I/O (readdir, readFile from fs/promises). This fixes hanging issues in session_search and other tools caused by blocking filesystem operations.

Changes:
- storage.ts: getAllSessions, readSessionMessages, getSessionInfo now async
- utils.ts: Updated utility functions to be async-compatible
- tools.ts: Added await calls for async storage functions
- storage.test.ts, utils.test.ts: Updated tests with async/await patterns

This resolves the session_search tool hang issue and improves overall responsiveness.

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

src/tools/session-manager/utils.test.ts

@@ -1,21 +1,39 @@
 import { describe, test, expect } from "bun:test"
-import { formatSessionList, formatSessionMessages, formatSessionInfo, formatSearchResults, filterSessionsByDate, searchInSession } from "./utils"
+import {
+  formatSessionList,
+  formatSessionMessages,
+  formatSessionInfo,
+  formatSearchResults,
+  filterSessionsByDate,
+  searchInSession,
+} from "./utils"
 import type { SessionInfo, SessionMessage, SearchResult } from "./types"
 
 describe("session-manager utils", () => {
-  test("formatSessionList handles empty array", () => {
-    const result = formatSessionList([])
-    
+  test("formatSessionList handles empty array", async () => {
+    // #given
+    const sessions: string[] = []
+
+    // #when
+    const result = await formatSessionList(sessions)
+
+    // #then
     expect(result).toContain("No sessions found")
   })
 
   test("formatSessionMessages handles empty array", () => {
-    const result = formatSessionMessages([])
-    
+    // #given
+    const messages: SessionMessage[] = []
+
+    // #when
+    const result = formatSessionMessages(messages)
+
+    // #then
     expect(result).toContain("No messages")
   })
 
   test("formatSessionMessages includes message content", () => {
+    // #given
     const messages: SessionMessage[] = [
       {
         id: "msg_001",
@@ -24,14 +42,17 @@ describe("session-manager utils", () => {
         parts: [{ id: "prt_001", type: "text", text: "Hello world" }],
       },
     ]
-    
+
+    // #when
     const result = formatSessionMessages(messages)
-    
+
+    // #then
     expect(result).toContain("user")
     expect(result).toContain("Hello world")
   })
 
   test("formatSessionMessages includes todos when requested", () => {
+    // #given
     const messages: SessionMessage[] = [
       {
         id: "msg_001",
@@ -40,20 +61,22 @@ describe("session-manager utils", () => {
         parts: [{ id: "prt_001", type: "text", text: "Test" }],
       },
     ]
-    
     const todos = [
       { id: "1", content: "Task 1", status: "completed" as const },
       { id: "2", content: "Task 2", status: "pending" as const },
     ]
-    
+
+    // #when
     const result = formatSessionMessages(messages, true, todos)
-    
+
+    // #then
     expect(result).toContain("Todos")
     expect(result).toContain("Task 1")
     expect(result).toContain("Task 2")
   })
 
   test("formatSessionInfo includes all metadata", () => {
+    // #given
     const info: SessionInfo = {
       id: "ses_test123",
       message_count: 42,
@@ -65,9 +88,11 @@ describe("session-manager utils", () => {
       todos: [{ id: "1", content: "Test", status: "pending" }],
       transcript_entries: 123,
     }
-    
+
+    // #when
     const result = formatSessionInfo(info)
-    
+
+    // #then
     expect(result).toContain("ses_test123")
     expect(result).toContain("42")
     expect(result).toContain("build, oracle")
@@ -75,12 +100,18 @@ describe("session-manager utils", () => {
   })
 
   test("formatSearchResults handles empty array", () => {
-    const result = formatSearchResults([])
-    
+    // #given
+    const results: SearchResult[] = []
+
+    // #when
+    const result = formatSearchResults(results)
+
+    // #then
     expect(result).toContain("No matches")
   })
 
   test("formatSearchResults formats matches correctly", () => {
+    // #given
     const results: SearchResult[] = [
       {
         session_id: "ses_test123",
@@ -91,9 +122,11 @@ describe("session-manager utils", () => {
         timestamp: Date.now(),
       },
     ]
-    
+
+    // #when
     const result = formatSearchResults(results)
-    
+
+    // #then
     expect(result).toContain("Found 1 matches")
     expect(result).toContain("ses_test123")
     expect(result).toContain("msg_001")
@@ -101,17 +134,26 @@ describe("session-manager utils", () => {
     expect(result).toContain("Matches: 3")
   })
 
-  test("filterSessionsByDate filters correctly", () => {
+  test("filterSessionsByDate filters correctly", async () => {
+    // #given
     const sessionIDs = ["ses_001", "ses_002", "ses_003"]
-    
-    const result = filterSessionsByDate(sessionIDs)
-    
+
+    // #when
+    const result = await filterSessionsByDate(sessionIDs)
+
+    // #then
     expect(Array.isArray(result)).toBe(true)
   })
 
-  test("searchInSession finds matches case-insensitively", () => {
-    const results = searchInSession("ses_nonexistent", "test", false)
-    
+  test("searchInSession finds matches case-insensitively", async () => {
+    // #given
+    const sessionID = "ses_nonexistent"
+    const query = "test"
+
+    // #when
+    const results = await searchInSession(sessionID, query, false)
+
+    // #then
     expect(Array.isArray(results)).toBe(true)
     expect(results.length).toBe(0)
   })