fix(sessions): fold Cursor Tasks under Agent Sub-Sessions like Codex (#262)

* fix(sessions): fold Cursor Tasks under Agent Sub-Sessions like Codex

Cursor IDE Tasks use a child session_id while transcript_path still points at
the parent chat, which created duplicate cards. Honor separate/merge/hide,
keep closed subagent ids across Stop (and idle-orphan merge drops), deny late
Permission/AskUserQuestion/Question for closed agent ids, drop idle orphans
without resuscitating via a shared IDE pid, fill missing parent identity from
merge-first Task hooks, reopen Cursor Tasks via beforeSubmitPrompt after Stop,
keep the parent active while folded Tasks run, and avoid dual-tailing the
parent transcript when splitting to separate cards.

* fix(sessions): harden Cursor Task fold permission and Stop edge cases

Keep folded deny/answer from idling the parent, drop idle orphans without
overwriting live Tasks, and only self-tombstone foldable separate Task cards.

* fix(appstate): allow AppState deinit off the main actor

Async XCTest teardown released AppState off MainActor and trapped in
assumeIsolated; use weak-boxed FSEvents teardown so discovery stays safe.

Author: zephyr110

Sources/CodeIsland/AppState.swift

@@ -312,6 +312,8 @@ class HookServer {
     private static let pluginMarkerBytes = Data("_via_plugin".utf8)
     private static let sourceMarkerBytes = Data(#""_source""#.utf8)
     private static let codexMarkerBytes = Data("codex".utf8)
+    private static let cursorTranscriptMarkerBytes = Data("agent-transcripts".utf8)
+    private static let cursorSourceMarkerBytes = Data("cursor".utf8)
 
     private static func codexSubagentMetadata(from raw: [String: Any]) -> CodexSubagentMetadata? {
         guard let path = nonEmptyString(raw["transcript_path"]) else { return nil }
@@ -346,15 +348,44 @@ class HookServer {
     }
 
     private func routeSubsessionPayloadIfNeeded(data: Data) -> (processedData: Data, responseData: Data?) {
-        let mayNeedRouting = data.range(of: Self.pluginMarkerBytes) != nil
+        let mayNeedPluginOrCodex = data.range(of: Self.pluginMarkerBytes) != nil
             || (data.range(of: Self.sourceMarkerBytes) != nil && data.range(of: Self.codexMarkerBytes) != nil)
-        guard mayNeedRouting,
+        let mayNeedCursor = data.range(of: Self.cursorTranscriptMarkerBytes) != nil
+            && data.range(of: Self.cursorSourceMarkerBytes) != nil
+
+        let mode = UserDefaults.standard.string(forKey: SettingsKey.pluginSessionMode)
+            ?? SettingsDefaults.pluginSessionMode
+
+        // Cursor Task routing is a no-op in separate mode; skip JSON parse when
+        // the payload is Cursor-only (Codex/plugin may still need it below).
+        if mayNeedCursor && !mayNeedPluginOrCodex && mode != "hide" && mode != "merge" {
+            return (data, nil)
+        }
+
+        guard mayNeedPluginOrCodex || mayNeedCursor,
               let raw = try? JSONSerialization.jsonObject(with: data) as? [String: Any] else {
             return (data, nil)
         }
 
-        let mode = UserDefaults.standard.string(forKey: SettingsKey.pluginSessionMode)
-            ?? SettingsDefaults.pluginSessionMode
+        // Cursor Task/subagent: apply Agent Sub-Sessions (separate / merge / hide).
+        switch CursorSubsessionRouter.decide(raw: raw, mode: mode) {
+        case .leave:
+            break
+        case .hide:
+            return (data, Self.hiddenPluginResponse(for: raw))
+        case .merge(let parentSessionId, let childSessionId):
+            var rewritten = raw
+            CursorSubsessionRouter.applyMerge(
+                to: &rewritten,
+                parentSessionId: parentSessionId,
+                childSessionId: childSessionId
+            )
+            if let newData = try? JSONSerialization.data(withJSONObject: rewritten) {
+                return (newData, nil)
+            }
+            return (data, nil)
+        }
+
         guard mode == "hide" || mode == "merge" else {
             return (data, nil)
         }
@@ -414,13 +445,11 @@ class HookServer {
     }
 
     private func processRequest(data: Data, connection: NWConnection) {
-        // Sub-session mode pre-filter (#123, #151): events that arrived through a
-        // plugin proxy (`_via_plugin`) or from a Codex native subagent can be
-        // merged into the matching main session, hidden, or kept separate per
-        // the user's setting. "separate" preserves prior behavior.
+        // Sub-session pre-filter (#123, #151): plugin, Codex, or Cursor Task hooks
+        // (Cursor: transcript parent ≠ session_id) follow Agent Sub-Sessions —
+        // merge into the parent, hide, or keep separate.
         //
-        // Cheap byte probes first — JSONSerialization on every PostToolUse on
-        // the main thread is not free.
+        // Cheap byte probes first; avoid JSONSerialization on every PostToolUse.
         let routed = routeSubsessionPayloadIfNeeded(data: data)
         if let responseData = routed.responseData {
             sendResponse(connection: connection, data: responseData)

Sources/CodeIsland/HookServer.swift

@@ -126,7 +126,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "Tool History Limit",
         "tool_history_limit_desc": "Max number of recent tool calls shown per session",
         "plugin_session_mode": "Agent Sub-Sessions",
-        "plugin_session_mode_desc": "How to show child sessions spawned by agents, including Codex subagents and plugin hook events (e.g. omo in OpenCode)",
+        "plugin_session_mode_desc": "How to show child sessions spawned by agents, including Codex subagents, Cursor IDE Task/subagents, and plugin hook events (e.g. omo in OpenCode)",
         "plugin_session_mode_separate": "Show separately",
         "plugin_session_mode_merge": "Merge into main",
         "plugin_session_mode_hide": "Hide",
@@ -470,7 +470,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "Tool-Verlaufslimit",
         "tool_history_limit_desc": "Maximale Anzahl der zuletzt angezeigten Tool-Aufrufe pro Sitzung",
         "plugin_session_mode": "Agent-Sub-Sitzungen",
-        "plugin_session_mode_desc": "Darstellung von durch Agenten gestarteten Kind-Sitzungen, einschließlich Codex-Subagenten und Plugin-Hook-Ereignissen (z. B. omo in OpenCode)",
+        "plugin_session_mode_desc": "Darstellung von durch Agenten gestarteten Kind-Sitzungen, einschließlich Codex-Subagenten, Cursor-IDE-Task/Subagenten und Plugin-Hook-Ereignissen (z. B. omo in OpenCode)",
         "plugin_session_mode_separate": "Separat anzeigen",
         "plugin_session_mode_merge": "In Hauptsitzung zusammenführen",
         "plugin_session_mode_hide": "Ausblenden",
@@ -810,7 +810,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "工具历史上限",
         "tool_history_limit_desc": "每个会话显示的最近工具调用数量上限",
         "plugin_session_mode": "Agent 子会话",
-        "plugin_session_mode_desc": "处理由 agent 派生的子会话，包括 Codex subagent 和插件 hook 事件（例如 OpenCode 中的 omo）",
+        "plugin_session_mode_desc": "处理由 agent 派生的子会话，包括 Codex subagent、Cursor IDE Task/subagent 和插件 hook 事件（例如 OpenCode 中的 omo）",
         "plugin_session_mode_separate": "独立显示",
         "plugin_session_mode_merge": "合并到主会话",
         "plugin_session_mode_hide": "隐藏",
@@ -1154,7 +1154,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "工具歷史上限",
         "tool_history_limit_desc": "每個會話顯示的最近工具呼叫數量上限",
         "plugin_session_mode": "Agent 子會話",
-        "plugin_session_mode_desc": "處理由 agent 衍生的子會話，包括 Codex subagent 和外掛 hook 事件（例如 OpenCode 中的 omo）",
+        "plugin_session_mode_desc": "處理由 agent 衍生的子會話，包括 Codex subagent、Cursor IDE Task/subagent 和外掛 hook 事件（例如 OpenCode 中的 omo）",
         "plugin_session_mode_separate": "獨立顯示",
         "plugin_session_mode_merge": "合併到主會話",
         "plugin_session_mode_hide": "隱藏",
@@ -1498,7 +1498,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "ツール履歴の上限",
         "tool_history_limit_desc": "セッションごとに表示する最近のツール呼び出し数の上限です",
         "plugin_session_mode": "エージェントのサブセッション",
-        "plugin_session_mode_desc": "Codex subagent やプラグイン hook イベントなど、エージェントから派生した子セッションの表示方法を選択します（例: OpenCode の omo）",
+        "plugin_session_mode_desc": "Codex subagent、Cursor IDE Task/subagent、プラグイン hook イベントなど、エージェントから派生した子セッションの表示方法を選択します（例: OpenCode の omo）",
         "plugin_session_mode_separate": "別々に表示",
         "plugin_session_mode_merge": "メインセッションに統合",
         "plugin_session_mode_hide": "非表示",
@@ -1842,7 +1842,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "도구 기록 제한",
         "tool_history_limit_desc": "세션별로 표시할 최근 도구 호출의 최대 개수입니다",
         "plugin_session_mode": "에이전트 하위 세션",
-        "plugin_session_mode_desc": "Codex subagent 및 플러그인 hook 이벤트 등 에이전트가 만든 하위 세션을 표시하는 방식 (예: OpenCode의 omo)",
+        "plugin_session_mode_desc": "Codex subagent, Cursor IDE Task/subagent 및 플러그인 hook 이벤트 등 에이전트가 만든 하위 세션을 표시하는 방식 (예: OpenCode의 omo)",
         "plugin_session_mode_separate": "별도로 표시",
         "plugin_session_mode_merge": "메인 세션으로 병합",
         "plugin_session_mode_hide": "숨김",
@@ -2186,7 +2186,7 @@ final class L10n: ObservableObject {
         "tool_history_limit": "Araç Geçmişi Limiti",
         "tool_history_limit_desc": "Oturum başına gösterilen son araç çağrı sayısı",
         "plugin_session_mode": "Ajan Alt Oturumları",
-        "plugin_session_mode_desc": "Codex subagent'ları ve eklenti hook olayları dahil, ajanların başlattığı alt oturumların nasıl gösterileceği (örn: OpenCode içinde omo)",
+        "plugin_session_mode_desc": "Codex subagent'ları, Cursor IDE Task/subagent'ları ve eklenti hook olayları dahil, ajanların başlattığı alt oturumların nasıl gösterileceği (örn: OpenCode içinde omo)",
         "plugin_session_mode_separate": "Ayrı göster",
         "plugin_session_mode_merge": "Ana oturuma birleştir",
         "plugin_session_mode_hide": "Gizle",

Sources/CodeIsland/L10n.swift

@@ -31,6 +31,10 @@ struct PersistedSession: Codable {
     let cliStartTime: Date?
     let startTime: Date
     let lastActivity: Date
+    /// Absolute JSONL path for session fold and transcript tailing.
+    let transcriptPath: String?
+    /// Closed subagent ids; kept across relaunch so merge cannot revive them.
+    let closedSubagentIds: [String]?
 }
 
 enum SessionPersistence {
@@ -66,7 +70,9 @@ enum SessionPersistence {
                 cliPid: s.cliPid,
                 cliStartTime: s.cliStartTime,
                 startTime: s.startTime,
-                lastActivity: s.lastActivity
+                lastActivity: s.lastActivity,
+                transcriptPath: s.transcriptPath,
+                closedSubagentIds: s.closedSubagentIds.isEmpty ? nil : Array(s.closedSubagentIds).sorted()
             )
         }
         do {

Sources/CodeIsland/SessionPersistence.swift

@@ -0,0 +1,114 @@
+import Foundation
+
+/// Maps Cursor Task/subagent hooks onto their parent chat card.
+///
+/// Child hooks use a different `session_id`, but `transcript_path` still points at
+/// `…/agent-transcripts/<parentId>/…`. Without rewriting, each Task appears as a
+/// duplicate Cursor card for the same IDE conversation.
+public enum CursorSessionFolding {
+    /// UUID segment under `agent-transcripts/`.
+    private static let uuidDirPattern = #"^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$"#
+
+    /// Parent conversation id from a Cursor `transcript_path`, when present.
+    ///
+    /// Recognized layouts:
+    /// - `…/agent-transcripts/<parentId>/<parentId>.jsonl`
+    /// - `…/agent-transcripts/<parentId>/subagents/<childId>.jsonl`
+    public static func parentConversationId(fromTranscriptPath path: String) -> String? {
+        let trimmed = path.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty else { return nil }
+
+        let parts = (trimmed as NSString).pathComponents
+        guard let transcriptsIdx = parts.lastIndex(of: "agent-transcripts"),
+              transcriptsIdx + 1 < parts.count else {
+            return nil
+        }
+
+        let parentCandidate = parts[transcriptsIdx + 1]
+        guard parentCandidate.range(of: uuidDirPattern, options: .regularExpression) != nil else {
+            return nil
+        }
+        return parentCandidate
+    }
+
+    /// Parent id when `childSessionId` is a Task of that conversation
+    /// (`transcript_path` parent ≠ `childSessionId`).
+    public static func foldTarget(childSessionId: String, transcriptPath: String?) -> String? {
+        let child = childSessionId.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !child.isEmpty,
+              let path = transcriptPath,
+              let parentId = parentConversationId(fromTranscriptPath: path),
+              parentId != child else {
+            return nil
+        }
+        return parentId
+    }
+}
+
+/// How to handle a Cursor Task/subagent hook under Agent Sub-Sessions.
+public enum CursorSubsessionRouteDecision: Equatable {
+    case leave
+    case hide
+    case merge(parentSessionId: String, childSessionId: String)
+}
+
+public enum CursorSubsessionRouter {
+    /// Apply Agent Sub-Sessions (`separate` / `merge` / `hide`) to Cursor hooks.
+    /// Same three modes as Codex and plugin children.
+    public static func decide(raw: [String: Any], mode: String) -> CursorSubsessionRouteDecision {
+        let normalizedSource = SessionSnapshot.normalizedSupportedSource(
+            (raw["_source"] as? String) ?? (raw["source"] as? String)
+        )
+        guard normalizedSource == "cursor" || normalizedSource == "cursor-cli" else {
+            return .leave
+        }
+
+        let childSessionId = nonEmptyString(raw["session_id"]) ?? nonEmptyString(raw["sessionId"])
+        guard let childSessionId else { return .leave }
+
+        let transcriptPath = nonEmptyString(raw["transcript_path"]) ?? nonEmptyString(raw["transcriptPath"])
+        guard let parentId = CursorSessionFolding.foldTarget(
+            childSessionId: childSessionId,
+            transcriptPath: transcriptPath
+        ) else {
+            return .leave
+        }
+
+        switch mode {
+        case "hide":
+            return .hide
+        case "merge":
+            return .merge(parentSessionId: parentId, childSessionId: childSessionId)
+        default:
+            // separate (or unknown): leave as its own session card
+            return .leave
+        }
+    }
+
+    /// Rewrite the hook onto the parent session and attach `agent_id` = child.
+    public static func applyMerge(
+        to raw: inout [String: Any],
+        parentSessionId: String,
+        childSessionId: String
+    ) {
+        raw["session_id"] = parentSessionId
+        raw["agent_id"] = nonEmptyString(raw["agent_id"]) ?? childSessionId
+        if nonEmptyString(raw["agent_type"]) == nil {
+            raw["agent_type"] = "cursor-subagent"
+        }
+        raw["_cursor_subagent"] = true
+        raw["_cursor_subagent_session_id"] = childSessionId
+        if let eventName = nonEmptyString(raw["hook_event_name"])
+            ?? nonEmptyString(raw["hookEventName"])
+            ?? nonEmptyString(raw["event_name"])
+            ?? nonEmptyString(raw["eventName"]) {
+            raw["_cursor_subagent_event"] = EventNormalizer.normalize(eventName)
+        }
+    }
+
+    private static func nonEmptyString(_ value: Any?) -> String? {
+        guard let string = value as? String else { return nil }
+        let trimmed = string.trimmingCharacters(in: .whitespacesAndNewlines)
+        return trimmed.isEmpty ? nil : trimmed
+    }
+}