feat(native): fork a session, here or into a worktree

CHANGELOG.md

@@ -9,6 +9,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- **Fork a session in the native window.** Right-click a card and pick
+  Fork › Here to carry its conversation on in a new card right under it, in
+  the same checkout, or Fork › Worktree… to take it to a new worktree along
+  with your uncommitted changes. The copy is named after the original
+  ("auth-refactor 2") and wears a fork mark. Claude Code, Codex and opencode
+  only: the other providers only resume.
 - **The native window warns when two cards run one conversation.** Resuming,
   from inside an agent's own TUI, a conversation another card already has
   open raises a warning in the bottom-right corner; Switch closes the card

README.es.md

@@ -128,7 +128,7 @@ porque lee lo que cada CLI deja escrito y no hay dos que anoten las mismas cosas
 | Buscar en la conversación desde la paleta | sí | sí | sí | sí | sí | sí | no | sí |
 | Reanudar una conversación iniciada fuera de lich, desde la pestaña Historial de la paleta | sí | sí | sí | sí | sí | Linux; macOS y Windows sin probar | sí | sí |
 | Un pegado largo puede llegar como texto editable en vez de un marcador plegado (Ajustes › Proveedores, desactivado por defecto) | sí | no | no | sí | no medido | no, se convierte en un adjunto `paste_N.txt` | no | sí |
-| Bifurcar una conversación en un nuevo worktree | sí | sí | no | sí | no | no | no | no |
+| Bifurcar una conversación en un nuevo worktree, o en su propio checkout en la ventana nativa | sí | sí | no | sí | no | no | no | no |
 | Aviso en la ventana nativa cuando retomas, desde la propia app del agente, una conversación que otra tarjeta tiene abierta | sí | en tu próximo prompt | en tu próximo prompt, sin probar | no | no | en su próxima llamada a una tool | no | sí |
 | Abrir una sesión con un esfuerzo de razonamiento elegido | sí | sí | sí | no | sí | no | en el nombre del modelo | sí |
 | Abrir una sesión con ultracode activado | sí | no | no | no | no | no | no | no |

README.ja.md

@@ -119,7 +119,7 @@ lich は各 CLI が書き残したものを読むので、書き残す内容は
 | パレットから会話を検索 | あり | あり | あり | あり | あり | あり | なし | あり |
 | lich の外で始めた会話を、パレットの History タブから再開 | あり | あり | あり | あり | あり | Linux のみ。macOS と Windows は未検証 | あり | あり |
 | 長いペーストを、折りたたまれたプレースホルダーではなく編集可能なテキストとして貼り付けられる（Settings › Providers、既定ではオフ） | あり | なし | なし | あり | 未計測 | なし（`paste_N.txt` の添付になる） | なし | あり |
-| 会話を新しいワークツリーにフォーク | あり | あり | なし | あり | なし | なし | なし | なし |
+| 会話を新しいワークツリーにフォーク（ネイティブウィンドウでは同じチェックアウト内にも） | あり | あり | なし | あり | なし | なし | なし | なし |
 | 別のカードで開いている会話をエージェント自身のアプリで再開すると、ネイティブウィンドウに警告 | あり | 次のプロンプトで | 次のプロンプトで（未検証） | なし | なし | 次のツール呼び出しで | なし | あり |
 | 推論エフォートを指定してセッションを開く | あり | あり | あり | なし | あり | なし | モデル名で指定 | あり |
 | ultracode をオンにしてセッションを開く | あり | なし | なし | なし | なし | なし | なし | なし |

README.ko.md

@@ -116,7 +116,7 @@ lich로 할 수 있는 일:
 | 팔레트에서 대화 검색 | 예 | 예 | 예 | 예 | 예 | 예 | 아니요 | 예 |
 | lich 밖에서 시작한 대화를 팔레트의 History 탭에서 재개 | 예 | 예 | 예 | 예 | 예 | Linux; macOS와 Windows는 미검증 | 예 | 예 |
 | 긴 붙여 넣기를 접힌 자리 표시자 대신 편집 가능한 텍스트로 넣기(Settings › Providers, 기본값 꺼짐) | 예 | 아니요 | 아니요 | 예 | 측정 안 됨 | 아니요, `paste_N.txt` 첨부 파일이 됨 | 아니요 | 예 |
-| 대화를 새 worktree로 포크 | 예 | 예 | 아니요 | 예 | 아니요 | 아니요 | 아니요 | 아니요 |
+| 대화를 새 worktree로 포크, 네이티브 창에서는 같은 체크아웃에도 포크 | 예 | 예 | 아니요 | 예 | 아니요 | 아니요 | 아니요 | 아니요 |
 | 다른 카드에 열려 있는 대화를 에이전트 자체 앱에서 재개하면 네이티브 창에 경고 | 예 | 다음 프롬프트에서 | 다음 프롬프트에서, 미검증 | 아니요 | 아니요 | 다음 도구 호출에서 | 아니요 | 예 |
 | 원하는 reasoning effort로 세션 열기 | 예 | 예 | 예 | 아니요 | 예 | 아니요 | 모델 이름으로 | 예 |
 | ultracode를 켠 채로 세션 열기 | 예 | 아니요 | 아니요 | 아니요 | 아니요 | 아니요 | 아니요 | 아니요 |

README.md

@@ -120,7 +120,7 @@ reads what each CLI writes down and no two of them write down the same things.
 | Search the conversation from the palette | yes | yes | yes | yes | yes | yes | no | yes |
 | Resume a conversation started outside lich, from the palette's History tab | yes | yes | yes | yes | yes | Linux; macOS and Windows untested | yes | yes |
 | A long paste can land as editable text instead of a folded placeholder (Settings › Providers, off by default) | yes | no | no | yes | not measured | no, it becomes a `paste_N.txt` attachment | no | yes |
-| Fork a conversation into a new worktree | yes | yes | no | yes | no | no | no | no |
+| Fork a conversation into a new worktree, or in its own checkout in the native window | yes | yes | no | yes | no | no | no | no |
 | Warned in the native window when you resume, from the agent's own app, a conversation another card has open | yes | on your next prompt | on your next prompt, untested | no | no | at its next tool call | no | yes |
 | Open a session at a chosen reasoning effort | yes | yes | yes | no | yes | no | in the model name | yes |
 | Open a session with ultracode on | yes | no | no | no | no | no | no | no |

README.pt-BR.md

@@ -131,7 +131,7 @@ mesmas coisas.
 | Pesquisar a conversa pela paleta | sim | sim | sim | sim | sim | sim | não | sim |
 | Retomar pela aba Histórico da paleta uma conversa iniciada fora do lich | sim | sim | sim | sim | sim | Linux; macOS e Windows não testados | sim | sim |
 | Um paste longo pode chegar como texto editável em vez de um marcador dobrado (Configurações › Provedores, desligado por padrão) | sim | não | não | sim | não medido | não, vira um anexo `paste_N.txt` | não | sim |
-| Fazer fork de uma conversa para uma nova worktree | sim | sim | não | sim | não | não | não | não |
+| Fazer fork de uma conversa para uma nova worktree, ou no mesmo checkout na janela nativa | sim | sim | não | sim | não | não | não | não |
 | Aviso na janela nativa quando você retoma, pelo próprio app do agente, uma conversa que outro card tem aberta | sim | no seu próximo prompt | no seu próximo prompt, não testado | não | não | na próxima chamada de tool | não | sim |
 | Abrir uma sessão com um esforço de raciocínio escolhido | sim | sim | sim | não | sim | não | no nome do modelo | sim |
 | Abrir uma sessão com o ultracode ligado | sim | não | não | não | não | não | não | não |

README.ru.md

@@ -132,7 +132,7 @@ lich вообще не запускается.
 | Поиск по разговору из палитры | да | да | да | да | да | да | нет | да |
 | Возобновление разговора, начатого вне lich, со вкладки «История» палитры | да | да | да | да | да | Linux; macOS и Windows не проверялись | да | да |
 | Длинная вставка может попасть как редактируемый текст вместо свёрнутой заглушки (Настройки › Провайдеры, по умолчанию выключено) | да | нет | нет | да | не измерялось | нет, она становится вложением `paste_N.txt` | нет | да |
-| Форк разговора в новый worktree | да | да | нет | да | нет | нет | нет | нет |
+| Форк разговора в новый worktree, а в нативном окне и в том же checkout | да | да | нет | да | нет | нет | нет | нет |
 | Предупреждение в нативном окне, когда вы возобновляете в самом приложении агента разговор, открытый в другой карточке | да | при следующем промпте | при следующем промпте, не проверено | нет | нет | при следующем вызове инструмента | нет | да |
 | Открытие сессии с выбранным уровнем рассуждений | да | да | да | нет | да | нет | в названии модели | да |
 | Открытие сессии с включённым ultracode | да | нет | нет | нет | нет | нет | нет | нет |

README.zh-CN.md

@@ -108,7 +108,7 @@
 | 从命令面板搜索对话里说过的内容 | 有 | 有 | 有 | 有 | 有 | 有 | 无 | 有 |
 | 在命令面板的 History 页恢复在 lich 之外开始的对话 | 有 | 有 | 有 | 有 | 有 | Linux；macOS 和 Windows 未测 | 有 | 有 |
 | 长文本粘贴可以以可编辑的完整文本出现，而不是折叠成占位符（设置 › Providers，默认关闭） | 有 | 无 | 无 | 有 | 未测 | 无，会变成 `paste_N.txt` 附件 | 无 | 有 |
-| 把一段对话分叉到新的 worktree | 有 | 有 | 无 | 有 | 无 | 无 | 无 | 无 |
+| 把一段对话分叉到新的 worktree，在原生窗口中也可在同一检出内分叉 | 有 | 有 | 无 | 有 | 无 | 无 | 无 | 无 |
 | 在智能体自己的应用里恢复另一张卡片已打开的对话时，原生窗口发出警告 | 有 | 在你的下一个提示时 | 在你的下一个提示时，未测试 | 无 | 无 | 在它的下一次工具调用时 | 无 | 有 |
 | 按指定的推理强度打开会话 | 有 | 有 | 有 | 无 | 有 | 无 | 写在模型名里 | 有 |
 | 以 ultracode 模式打开会话 | 有 | 无 | 无 | 无 | 无 | 无 | 无 | 无 |

frontend/src/lib/api-types.ts

@@ -414,6 +414,9 @@ export interface StoredSession {
   originSessionId: string
   /** What that session was called at the time; all that survives its close. */
   originLabel: string
+  /** Whether the session was born branching its origin's conversation, rather
+   * than delegated or opened as a subagent. Only the native window reads it. */
+  forked?: boolean
   /** When the prompt below is due, in unix seconds; 0 for a session with
    * nothing waiting. One slot per session — scheduling again replaces it. */
   scheduledAt: number

internal/store/migrate.go

@@ -22,6 +22,7 @@ var migrations = []func(*sql.Tx) error{
 	addSessionColor,
 	addProviderSessionTombstones,
 	addSessionProfile,
+	addSessionForked,
 }
 
 // addSessionEffort is version 2: the reasoning effort a session was opened at,
@@ -123,6 +124,14 @@ func addSessionProfile(tx *sql.Tx) error {
 	return err
 }
 
+// addSessionForked is version 10: whether the session was born branching
+// another's conversation (MarkForked). The origin columns cannot say it: a
+// delegate and a subagent card carry an origin too.
+func addSessionForked(tx *sql.Tx) error {
+	_, err := tx.Exec(`ALTER TABLE sessions ADD COLUMN forked INTEGER NOT NULL DEFAULT 0`)
+	return err
+}
+
 // NewerSchemaError is an open refused because the database was written by a
 // newer lich than this one. Opening it anyway would let this binary write its
 // defaults over columns it does not know about, so it is not opened at all.

internal/store/mutations.go

@@ -364,14 +364,14 @@ func (s *Service) reopen(newSessionID, where string, args ...any) (*Session, err
 		row := tx.QueryRow(
 			`SELECT id, project_id, label, kind, path, provider_session_id, label_auto,
 			        model, effort, ultracode, subagent, entrypoint, sandbox, pinned, folder, color, origin_session_id, origin_label,
-			        scheduled_at, scheduled_prompt, fork_cost_offset, profile
+			        forked, scheduled_at, scheduled_prompt, fork_cost_offset, profile
 			   FROM sessions `+where,
 			args...,
 		)
 		if err := row.Scan(
 			&old.ID, &projectID, &old.Label, &old.Kind, &old.Path, &old.ProviderSessionID,
 			&labelAuto, &model, &effort, &ultracode, &subagent, &entrypoint, &sandbox, &old.Pinned, &folder, &color,
-			&old.OriginSessionID, &old.OriginLabel,
+			&old.OriginSessionID, &old.OriginLabel, &old.Forked,
 			&old.ScheduledAt, &old.ScheduledPrompt, &forkOffset, &profile,
 		); err != nil {
 			if errors.Is(err, sql.ErrNoRows) {
@@ -422,11 +422,11 @@ func (s *Service) reopen(newSessionID, where string, args ...any) (*Session, err
 			`INSERT INTO sessions
 			   (id, project_id, label, kind, path, provider_session_id, label_auto,
 			    model, effort, ultracode, subagent, entrypoint, sandbox, pinned, folder, color, origin_session_id, origin_label,
-			    scheduled_at, scheduled_prompt, fork_cost_offset, profile, position)
-			 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, `+nextSessionPosition+`)`,
+			    forked, scheduled_at, scheduled_prompt, fork_cost_offset, profile, position)
+			 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, `+nextSessionPosition+`)`,
 			newSessionID, projectID, old.Label, old.Kind, old.Path, old.ProviderSessionID, labelAuto,
 			model, effort, ultracode, subagent, entrypoint, sandbox, old.Pinned, folder, color, old.OriginSessionID, old.OriginLabel,
-			old.ScheduledAt, old.ScheduledPrompt, forkOffset, profile, projectID,
+			old.Forked, old.ScheduledAt, old.ScheduledPrompt, forkOffset, profile, projectID,
 		); err != nil {
 			return fmt.Errorf("reinsert session %q: %w", newSessionID, err)
 		}
@@ -453,6 +453,7 @@ func (s *Service) reopen(newSessionID, where string, args ...any) (*Session, err
 			Profile:           profile,
 			OriginSessionID:   old.OriginSessionID,
 			OriginLabel:       old.OriginLabel,
+			Forked:            old.Forked,
 			ScheduledAt:       old.ScheduledAt,
 			ScheduledPrompt:   old.ScheduledPrompt,
 		}
@@ -821,6 +822,15 @@ func (s *Service) InheritSubagent(sessionID, forkedFrom string) error {
 	return nil
 }
 
+// MarkForked records that sessionID was born branching its origin's
+// conversation, written by the window that opens the fork along with the row.
+func (s *Service) MarkForked(sessionID string) error {
+	if _, err := s.db.Exec(`UPDATE sessions SET forked = 1 WHERE id = ?`, sessionID); err != nil {
+		return fmt.Errorf("mark %q forked: %w", sessionID, err)
+	}
+	return nil
+}
+
 // InheritUltracode turns ultracode on for a fork when the session that ran the
 // conversation it branches, forkedFrom, has it on. The fork's row is a fresh
 // insert that knows nothing of its parent, and Claude Code drops ultracode on

internal/store/origin_test.go

@@ -97,3 +97,37 @@ func TestReopenWorktreeSessionCarriesTheOrigin(t *testing.T) {
 		t.Errorf("reloaded origin = %+v, want the parent it was opened from", reloaded)
 	}
 }
+
+// TestMarkForkedRidesTheRowThroughAReopen: a fork is told apart from a
+// delegate or a subagent, which carry an origin too, by its own mark, and a
+// park and resume is not what makes a card stop being a fork.
+func TestMarkForkedRidesTheRowThroughAReopen(t *testing.T) {
+	svc := newTestStore(t)
+	_ = svc.AddProject("p1", "alpha", "/tmp/alpha")
+	_ = svc.AddSession("p1", "keep", "auth-refactor", "claude", "", 1, "")
+	_ = svc.AddSessionFrom("p1", "fork", "auth-refactor 2", "claude", "", 2, "keep", "auth-refactor", "")
+	_ = svc.AddSessionFrom("p1", "worker", "worker", "claude", "", 3, "keep", "auth-refactor", "")
+	if err := svc.MarkForked("fork"); err != nil {
+		t.Fatalf("MarkForked: %v", err)
+	}
+
+	forked := func() map[string]bool {
+		projects, _ := svc.LoadState()
+		got := map[string]bool{}
+		for _, s := range projects[0].Sessions {
+			got[s.ID] = s.Forked
+		}
+		return got
+	}
+	if got := forked(); !got["fork"] || got["worker"] || got["keep"] {
+		t.Fatalf("forked = %v, want only the fork marked", got)
+	}
+	_ = svc.CloseSession("p1", "fork", "keep")
+	restored, err := svc.ReopenSession("fork", "fork-again")
+	if err != nil || restored == nil || !restored.Forked {
+		t.Fatalf("reopen = %+v, %v; want the mark carried", restored, err)
+	}
+	if !forked()["fork-again"] {
+		t.Error("the reopened row lost its fork mark on reload")
+	}
+}

internal/store/store.go

@@ -400,6 +400,9 @@ type Session struct {
 	Profile         string `json:"profile"`
 	OriginSessionID string `json:"originSessionId"`
 	OriginLabel     string `json:"originLabel"`
+	// Forked is whether the session was born branching its origin's
+	// conversation, rather than delegated or opened as a subagent.
+	Forked bool `json:"forked"`
 	// ScheduledAt is when the prompt below is due, in unix seconds, 0 for a
 	// session with nothing waiting. It rides the session row so the card that
 	// draws the countdown and the relay that delivers it read the same hydration
@@ -690,7 +693,7 @@ func (s *Service) ProjectAt(path string) (string, string) {
 func (s *Service) sessionsOf(projectID string) ([]Session, error) {
 	rows, err := s.db.Query(
 		`SELECT id, label, kind, path, provider_session_id, entrypoint, sandbox, pinned,
-		        folder, color, profile, origin_session_id, origin_label, scheduled_at, scheduled_prompt, unread,
+		        folder, color, profile, origin_session_id, origin_label, forked, scheduled_at, scheduled_prompt, unread,
 		        mcp_servers, sandbox_links,
 		        EXISTS (SELECT 1 FROM session_last_turn WHERE session_id = sessions.id)
 		   FROM sessions WHERE project_id = ? AND is_open = 1 ORDER BY position, rowid`,
@@ -708,7 +711,7 @@ func (s *Service) sessionsOf(projectID string) ([]Session, error) {
 		if err := rows.Scan(
 			&sess.ID, &sess.Label, &sess.Kind, &sess.Path, &sess.ProviderSessionID,
 			&sess.Entrypoint, &sess.Sandbox, &sess.Pinned, &sess.Folder, &sess.Color, &sess.Profile,
-			&sess.OriginSessionID, &sess.OriginLabel,
+			&sess.OriginSessionID, &sess.OriginLabel, &sess.Forked,
 			&sess.ScheduledAt, &sess.ScheduledPrompt, &sess.Unread, &servers, &links,
 			&sess.HasLastTurn,
 		); err != nil {

internal/store/store_test.go

@@ -969,7 +969,7 @@ func TestOpenDropsTheTerminalThemeSetting(t *testing.T) {
 	_ = before.SetSetting("appearance.terminalTheme", "p1", "emerald")
 	_ = before.SetSetting("appearance.theme", "", "rose-pine")
 	_ = before.Close()
-	seedDB(t, path, `ALTER TABLE sessions DROP COLUMN effort; ALTER TABLE sessions DROP COLUMN ultracode; ALTER TABLE sessions DROP COLUMN subagent; ALTER TABLE session_costs DROP COLUMN reported; ALTER TABLE sessions DROP COLUMN color; ALTER TABLE sessions DROP COLUMN profile; DROP TABLE provider_session_tombstones; DROP TRIGGER sessions_tombstone_ad; DROP TRIGGER sessions_tombstone_ai; DROP TRIGGER sessions_tombstone_au; PRAGMA user_version = 0`)
+	seedDB(t, path, `ALTER TABLE sessions DROP COLUMN effort; ALTER TABLE sessions DROP COLUMN ultracode; ALTER TABLE sessions DROP COLUMN subagent; ALTER TABLE session_costs DROP COLUMN reported; ALTER TABLE sessions DROP COLUMN color; ALTER TABLE sessions DROP COLUMN profile; ALTER TABLE sessions DROP COLUMN forked; DROP TABLE provider_session_tombstones; DROP TRIGGER sessions_tombstone_ad; DROP TRIGGER sessions_tombstone_ai; DROP TRIGGER sessions_tombstone_au; PRAGMA user_version = 0`)
 
 	after, err := open(path)
 	if err != nil {