feat(tools): add session management tools for OpenCode sessions (#227)

* feat(tools): add session management tools for OpenCode sessions

- Add session_list tool for listing sessions with filtering
- Add session_read tool for reading session messages and history
- Add session_search tool for full-text search across sessions
- Add session_info tool for session metadata inspection
- Add comprehensive tests for storage, utils, and tools
- Update documentation in AGENTS.md

Closes #132

* fix(session-manager): add Windows compatibility for storage paths

- Create shared/data-path.ts utility for cross-platform data directory resolution
- On Windows: uses %LOCALAPPDATA% (e.g., C:\Users\Username\AppData\Local)
- On Unix: uses $XDG_DATA_HOME or ~/.local/share (XDG Base Directory spec)
- Update session-manager/constants.ts to use getOpenCodeStorageDir()
- Update hook-message-injector/constants.ts to use same utility
- Remove dependency on xdg-basedir package in session-manager
- Follows existing pattern from auto-update-checker for consistency

---------

Co-authored-by: sisyphus-dev-ai <sisyphus-dev-ai@users.noreply.github.com>

src/tools/session-manager/storage.ts

@@ -0,0 +1,176 @@
+import { existsSync, readdirSync, readFileSync } from "node:fs"
+import { join } from "node:path"
+import { MESSAGE_STORAGE, PART_STORAGE, TODO_DIR, TRANSCRIPT_DIR } from "./constants"
+import type { SessionMessage, SessionInfo, TodoItem } from "./types"
+
+export function getAllSessions(): string[] {
+  if (!existsSync(MESSAGE_STORAGE)) return []
+
+  const sessions: string[] = []
+
+  function scanDirectory(dir: string): void {
+    try {
+      for (const entry of readdirSync(dir, { withFileTypes: true })) {
+        if (entry.isDirectory()) {
+          const sessionPath = join(dir, entry.name)
+          const files = readdirSync(sessionPath)
+          if (files.some((f) => f.endsWith(".json"))) {
+            sessions.push(entry.name)
+          } else {
+            scanDirectory(sessionPath)
+          }
+        }
+      }
+    } catch {
+      return
+    }
+  }
+
+  scanDirectory(MESSAGE_STORAGE)
+  return [...new Set(sessions)]
+}
+
+export function getMessageDir(sessionID: string): string {
+  if (!existsSync(MESSAGE_STORAGE)) return ""
+
+  const directPath = join(MESSAGE_STORAGE, sessionID)
+  if (existsSync(directPath)) {
+    return directPath
+  }
+
+  for (const dir of readdirSync(MESSAGE_STORAGE)) {
+    const sessionPath = join(MESSAGE_STORAGE, dir, sessionID)
+    if (existsSync(sessionPath)) {
+      return sessionPath
+    }
+  }
+
+  return ""
+}
+
+export function sessionExists(sessionID: string): boolean {
+  return getMessageDir(sessionID) !== ""
+}
+
+export function readSessionMessages(sessionID: string): SessionMessage[] {
+  const messageDir = getMessageDir(sessionID)
+  if (!messageDir || !existsSync(messageDir)) return []
+
+  const messages: SessionMessage[] = []
+  for (const file of readdirSync(messageDir)) {
+    if (!file.endsWith(".json")) continue
+    try {
+      const content = readFileSync(join(messageDir, file), "utf-8")
+      const meta = JSON.parse(content)
+
+      const parts = readParts(meta.id)
+
+      messages.push({
+        id: meta.id,
+        role: meta.role,
+        agent: meta.agent,
+        time: meta.time,
+        parts,
+      })
+    } catch {
+      continue
+    }
+  }
+
+  return messages.sort((a, b) => {
+    const aTime = a.time?.created ?? 0
+    const bTime = b.time?.created ?? 0
+    if (aTime !== bTime) return aTime - bTime
+    return a.id.localeCompare(b.id)
+  })
+}
+
+function readParts(messageID: string): Array<{ id: string; type: string; [key: string]: unknown }> {
+  const partDir = join(PART_STORAGE, messageID)
+  if (!existsSync(partDir)) return []
+
+  const parts: Array<{ id: string; type: string; [key: string]: unknown }> = []
+  for (const file of readdirSync(partDir)) {
+    if (!file.endsWith(".json")) continue
+    try {
+      const content = readFileSync(join(partDir, file), "utf-8")
+      parts.push(JSON.parse(content))
+    } catch {
+      continue
+    }
+  }
+
+  return parts.sort((a, b) => a.id.localeCompare(b.id))
+}
+
+export function readSessionTodos(sessionID: string): TodoItem[] {
+  if (!existsSync(TODO_DIR)) return []
+
+  const todoFiles = readdirSync(TODO_DIR).filter((f) => f.includes(sessionID) && f.endsWith(".json"))
+
+  for (const file of todoFiles) {
+    try {
+      const content = readFileSync(join(TODO_DIR, file), "utf-8")
+      const data = JSON.parse(content)
+      if (Array.isArray(data)) {
+        return data.map((item) => ({
+          id: item.id || "",
+          content: item.content || "",
+          status: item.status || "pending",
+          priority: item.priority,
+        }))
+      }
+    } catch {
+      continue
+    }
+  }
+
+  return []
+}
+
+export function readSessionTranscript(sessionID: string): number {
+  if (!existsSync(TRANSCRIPT_DIR)) return 0
+
+  const transcriptFile = join(TRANSCRIPT_DIR, `${sessionID}.jsonl`)
+  if (!existsSync(transcriptFile)) return 0
+
+  try {
+    const content = readFileSync(transcriptFile, "utf-8")
+    return content.trim().split("\n").filter(Boolean).length
+  } catch {
+    return 0
+  }
+}
+
+export function getSessionInfo(sessionID: string): SessionInfo | null {
+  const messages = readSessionMessages(sessionID)
+  if (messages.length === 0) return null
+
+  const agentsUsed = new Set<string>()
+  let firstMessage: Date | undefined
+  let lastMessage: Date | undefined
+
+  for (const msg of messages) {
+    if (msg.agent) agentsUsed.add(msg.agent)
+    if (msg.time?.created) {
+      const date = new Date(msg.time.created)
+      if (!firstMessage || date < firstMessage) firstMessage = date
+      if (!lastMessage || date > lastMessage) lastMessage = date
+    }
+  }
+
+  const todos = readSessionTodos(sessionID)
+  const transcriptEntries = readSessionTranscript(sessionID)
+
+  return {
+    id: sessionID,
+    message_count: messages.length,
+    first_message: firstMessage,
+    last_message: lastMessage,
+    agents_used: Array.from(agentsUsed),
+    has_todos: todos.length > 0,
+    has_transcript: transcriptEntries > 0,
+    todos,
+    transcript_entries: transcriptEntries,
+  }
+}