feat(service): expose subscribe, input, exit status for ws handler

Co-Authored-By: Claude <noreply@anthropic.com>

internal/process/manager.go

@@ -23,6 +23,8 @@ type Manager interface {
 	Restart(workspaceID string, workspaceRoot string) error
 	Status(workspaceID string) Status
 	Subscribe(workspaceID string) (Subscription, error)
+	Stdin(workspaceID string) (io.WriteCloser, error)
+	ExitStatus(workspaceID string) (ExitInfo, error)
 }
 
 // LocalManager implements Manager using local OS processes.
@@ -237,6 +239,41 @@ func (m *LocalManager) Subscribe(workspaceID string) (Subscription, error) {
 	return sub, nil
 }
 
+// Stdin returns the stdin writer for the workspace process.
+func (m *LocalManager) Stdin(workspaceID string) (io.WriteCloser, error) {
+	return m.stdinOf(workspaceID)
+}
+
+// ExitStatus returns the exit status for the workspace process.
+func (m *LocalManager) ExitStatus(workspaceID string) (ExitInfo, error) {
+	return m.exitOf(workspaceID)
+}
+
+// stdinOf returns the session's stdin writer or CodeNotFound.
+func (m *LocalManager) stdinOf(workspaceID string) (io.WriteCloser, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	sess, ok := m.sessions[workspaceID]
+	if !ok {
+		return nil, util.New(util.CodeNotFound, "no running process")
+	}
+	return sess.Stdin, nil
+}
+
+// exitOf returns the session's recorded exit info or CodeNotFound.
+func (m *LocalManager) exitOf(workspaceID string) (ExitInfo, error) {
+	m.mu.Lock()
+	sess, ok := m.sessions[workspaceID]
+	m.mu.Unlock()
+	if !ok {
+		return ExitInfo{}, util.New(util.CodeNotFound, "no running process")
+	}
+
+	sess.mu.Lock()
+	defer sess.mu.Unlock()
+	return sess.Exit, nil
+}
+
 // ringBuffer is a fixed-size byte buffer that drops the oldest bytes when full.
 type ringBuffer struct {
 	mu   sync.Mutex