feat: update dashboard and process manager for unified launcher

Actualiza el dashboard TUI y el process manager para el modelo de launcher
unificado donde todos los agentes corren en un solo proceso.

Dashboard (pkg/tui):
- model.go: campos de estado del launcher (PID, uptime, memory, CPU, log size)
- model.go: ServerMenuOptions(running) contextual, AgentActionOptions(enabled)
- messages.go: MsgAgentsLoaded incluye estado del launcher, MsgServerActionDone/MsgRebuildDone simplificados
- update.go: intents nuevos (Enable/Disable agent, Start/Stop/Restart/Kill launcher)
- view.go: vista de servidor muestra stats del launcher, agentes muestran enabled/disabled

Shell adapter (shell/tui):
- adapter.go: reescrito para usar métodos unificados (StartUnified, StopUnified, ToggleEnabled, StatusAllUnified, UnifiedStats, UnifiedLogTail)

Process manager (shell/process):
- manager.go: métodos StartUnified, StopUnified, KillUnified, IsUnifiedRunning, UnifiedPID, UnifiedStats, UnifiedLogTail, StatusAllUnified, ToggleEnabled

Los agentes ya no se inician/detienen individualmente desde el dashboard.
Se habilitan/deshabilitan en config y se reinicia el launcher para aplicar.

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

pkg/tui/messages.go

@@ -3,34 +3,39 @@ package tui
 // Messages are pure data returned by the shell adapter.
 // They carry the result of an I/O operation back into the pure Update.
 
-// MsgAgentsLoaded carries refreshed agent data.
-type MsgAgentsLoaded struct{ Agents []AgentView }
+// MsgAgentsLoaded carries refreshed agent data + launcher status.
+type MsgAgentsLoaded struct {
+	Agents          []AgentView
+	LauncherRunning bool
+	LauncherPID     int
+	LauncherUptime  string
+	LauncherMemory  string
+	LauncherCPU     string
+	LauncherLogSize string
+}
 
-// MsgActionDone reports the result of an agent action (start/stop/kill/restart).
+// MsgActionDone reports the result of an action (start/stop/enable/disable).
 type MsgActionDone struct {
 	AgentID string
 	Action  string
 	Err     error
 }
 
-// MsgLogsLoaded carries log lines for the selected agent.
+// MsgLogsLoaded carries log lines for display.
 type MsgLogsLoaded struct{ Lines []string }
 
-// MsgServerActionDone reports the result of a server-wide bulk action.
+// MsgServerActionDone reports the result of a launcher action.
 type MsgServerActionDone struct {
-	Action   string
-	Total    int
-	Failed   int
-	Errors   []string
+	Action string
+	Err    error
 }
 
 // MsgRebuildDone reports the result of a rebuild & restart cycle.
 type MsgRebuildDone struct {
-	BuildOK   bool
-	BuildLog  string // last lines of build output
-	Restarted int    // agents restarted after build
-	Failed    int
-	Errors    []string
+	BuildOK  bool
+	BuildLog string // last lines of build output
+	Started  bool   // launcher started after build
+	Err      error
 }
 
 // MsgTick triggers a periodic refresh.