feat: controles de hot-reload por agente en el dashboard TUI

Añade opciones de Reload (hot-reload) separadas de Restart (reinicio
completo) en el dashboard, usando el mecanismo SIGHUP implementado en
el issue 0013.

Cambios en pkg/tui/ (capa pura):
- IntentReloadAgent: hot-reload de un agente individual via SIGHUP
- IntentReloadAll: hot-reload de todos los agentes via SIGHUP
- AgentActionOptions: añade "Reload" antes de "Restart" con descripciones
  clarificadas ("sin interrumpir los demás" vs "launcher completo")
- ServerMenuOptions (running): añade "Reload All" como primera opción
- executeAction: maneja "Reload" → IntentReloadAgent
- executeServerAction: maneja "Reload All" → IntentReloadAll
- Mensajes de estado diferenciados: "Reload OK — X recargado sin
  interrupciones" vs "Restart OK — launcher reiniciado"

Cambios en shell/tui/ (capa impura):
- reloadAgent(id): escribe run/reload.txt + SIGHUP; error si launcher
  no está corriendo (no hay fallback a full restart)
- reloadAll(): elimina reload.txt + SIGHUP; error si no está corriendo
- restartAgent(id): restaurado a su comportamiento original de
  stop+start completo del launcher

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pkg/tui/model.go

@@ -96,6 +96,7 @@ func TestMenuOptions() []MenuOption {
 func ServerMenuOptions(running bool) []MenuOption {
 	if running {
 		return []MenuOption{
+			{Label: "Reload All", Desc: "Hot-reload de todos los agentes (SIGHUP)"},
 			{Label: "Stop", Desc: "Detener el launcher"},
 			{Label: "Restart", Desc: "Reiniciar el launcher"},
 			{Label: "Kill", Desc: "SIGKILL forzado"},
@@ -115,13 +116,15 @@ func ServerMenuOptions(running bool) []MenuOption {
 func AgentActionOptions(enabled bool) []MenuOption {
 	if enabled {
 		return []MenuOption{
-			{Label: "Restart", Desc: "Reiniciar launcher para aplicar cambios"},
+			{Label: "Reload", Desc: "Hot-reload este agente (SIGHUP, sin interrumpir los demás)"},
+			{Label: "Restart", Desc: "Reiniciar el launcher completo (todos los agentes)"},
 			{Label: "Disable", Desc: "Desactivar agente (requiere restart)"},
 			{Label: "Logs", Desc: "Ver log del launcher"},
 		}
 	}
 	return []MenuOption{
-		{Label: "Restart", Desc: "Reiniciar launcher para aplicar cambios"},
+		{Label: "Reload", Desc: "Hot-reload este agente (SIGHUP, sin interrumpir los demás)"},
+		{Label: "Restart", Desc: "Reiniciar el launcher completo (todos los agentes)"},
 		{Label: "Enable", Desc: "Activar agente (requiere restart)"},
 		{Label: "Logs", Desc: "Ver log del launcher"},
 	}

pkg/tui/update.go

@@ -14,7 +14,9 @@ const (
 	// Agent-level
 	IntentEnableAgent  IntentKind = "enable_agent"
 	IntentDisableAgent IntentKind = "disable_agent"
-	IntentRestartAgent IntentKind = "restart_agent"
+	IntentReloadAgent  IntentKind = "reload_agent"  // hot-reload via SIGHUP (solo este agente)
+	IntentReloadAll    IntentKind = "reload_all"    // hot-reload via SIGHUP (todos los agentes)
+	IntentRestartAgent IntentKind = "restart_agent" // restart completo del launcher
 
 	// Unified launcher operations
 	IntentStartLauncher   IntentKind = "start_launcher"
@@ -74,8 +76,10 @@ func Update(model Model, msg interface{}) (Model, []Intent) {
 	case MsgActionDone:
 		if m.Err != nil {
 			model.StatusMsg = fmt.Sprintf("Error: %s %s: %v", m.Action, m.AgentID, m.Err)
+		} else if m.Action == "Reload" {
+			model.StatusMsg = fmt.Sprintf("Reload OK — %s recargado sin interrupciones", m.AgentID)
 		} else if m.Action == "Restart" {
-			model.StatusMsg = fmt.Sprintf("Restart OK — all agents reloaded")
+			model.StatusMsg = "Restart OK — launcher reiniciado"
 		} else {
 			model.StatusMsg = fmt.Sprintf("%s %s OK — restart launcher to apply", m.Action, m.AgentID)
 		}
@@ -84,6 +88,8 @@ func Update(model Model, msg interface{}) (Model, []Intent) {
 	case MsgServerActionDone:
 		if m.Err != nil {
 			model.StatusMsg = fmt.Sprintf("Error: %s: %v", m.Action, m.Err)
+		} else if m.Action == "Reload All" {
+			model.StatusMsg = "Reload All OK — SIGHUP enviado al launcher"
 		} else {
 			model.StatusMsg = fmt.Sprintf("%s OK", m.Action)
 		}
@@ -245,6 +251,9 @@ func executeAction(model Model, action string) (Model, []Intent) {
 	case "Disable":
 		model.StatusMsg = "Disabling " + id + "..."
 		return model, []Intent{{Kind: IntentDisableAgent, AgentID: id}}
+	case "Reload":
+		model.StatusMsg = "Hot-reloading " + id + "..."
+		return model, []Intent{{Kind: IntentReloadAgent, AgentID: id}}
 	case "Restart":
 		model.StatusMsg = "Restarting launcher (all agents)..."
 		return model, []Intent{{Kind: IntentRestartAgent, AgentID: id}}
@@ -302,6 +311,9 @@ func updateServerScreen(model Model, key KeyMsg) (Model, []Intent) {
 
 func executeServerAction(model Model, action string) (Model, []Intent) {
 	switch action {
+	case "Reload All":
+		model.StatusMsg = "Hot-reloading all agents..."
+		return model, []Intent{{Kind: IntentReloadAll}}
 	case "Start":
 		model.StatusMsg = "Starting launcher..."
 		return model, []Intent{{Kind: IntentStartLauncher}}

shell/tui/adapter.go

@@ -39,6 +39,12 @@ func (a *Adapter) RunIntent(intent puretui.Intent) tea.Cmd {
 	case puretui.IntentDisableAgent:
 		return a.disableAgent(intent.AgentID)
 
+	case puretui.IntentReloadAgent:
+		return a.reloadAgent(intent.AgentID)
+
+	case puretui.IntentReloadAll:
+		return a.reloadAll()
+
 	case puretui.IntentRestartAgent:
 		return a.restartAgent(intent.AgentID)
 
@@ -140,30 +146,57 @@ func (a *Adapter) disableAgent(id string) tea.Cmd {
 	}
 }
 
-func (a *Adapter) restartAgent(id string) tea.Cmd {
+// reloadAgent hot-reloads a single agent via SIGHUP without stopping the launcher.
+func (a *Adapter) reloadAgent(id string) tea.Cmd {
 	return func() tea.Msg {
 		pid := a.mgr.UnifiedPID()
 		if pid <= 0 {
-			// Launcher not running — fall back to full restart.
+			return puretui.MsgActionDone{AgentID: id, Action: "Reload",
-			_ = a.mgr.StopUnified()
+				Err: fmt.Errorf("el launcher no está corriendo")}
-			time.Sleep(500 * time.Millisecond)
-			err := a.mgr.StartUnified()
-			if err == nil {
-				time.Sleep(500 * time.Millisecond)
-			}
-			return puretui.MsgActionDone{AgentID: id, Action: "Restart", Err: err}
 		}
-
-		// Launcher is running — write target and send SIGHUP for hot-reload.
 		if id != "" {
-			_ = os.WriteFile("run/reload.txt", []byte(id), 0o644)
+			if err := os.WriteFile("run/reload.txt", []byte(id), 0o644); err != nil {
+				return puretui.MsgActionDone{AgentID: id, Action: "Reload", Err: err}
+			}
 		}
 		err := syscall.Kill(pid, syscall.SIGHUP)
 		if err != nil {
-			return puretui.MsgActionDone{AgentID: id, Action: "Restart", Err: err}
+			return puretui.MsgActionDone{AgentID: id, Action: "Reload", Err: err}
 		}
 		time.Sleep(1 * time.Second)
-		return puretui.MsgActionDone{AgentID: id, Action: "Restart", Err: nil}
+		return puretui.MsgActionDone{AgentID: id, Action: "Reload", Err: nil}
+	}
+}
+
+// reloadAll hot-reloads all agents via SIGHUP (no reload.txt → reload all).
+func (a *Adapter) reloadAll() tea.Cmd {
+	return func() tea.Msg {
+		pid := a.mgr.UnifiedPID()
+		if pid <= 0 {
+			return puretui.MsgServerActionDone{Action: "Reload All",
+				Err: fmt.Errorf("el launcher no está corriendo")}
+		}
+		// Remove stale reload.txt so the launcher reloads all agents.
+		_ = os.Remove("run/reload.txt")
+		err := syscall.Kill(pid, syscall.SIGHUP)
+		if err != nil {
+			return puretui.MsgServerActionDone{Action: "Reload All", Err: err}
+		}
+		time.Sleep(1 * time.Second)
+		return puretui.MsgServerActionDone{Action: "Reload All", Err: nil}
+	}
+}
+
+// restartAgent stops and restarts the whole launcher (full restart, all agents).
+func (a *Adapter) restartAgent(id string) tea.Cmd {
+	return func() tea.Msg {
+		_ = a.mgr.StopUnified()
+		time.Sleep(500 * time.Millisecond)
+		err := a.mgr.StartUnified()
+		if err == nil {
+			time.Sleep(500 * time.Millisecond)
+		}
+		return puretui.MsgActionDone{AgentID: id, Action: "Restart", Err: err}
 	}
 }