feat: sistema de personalidades enriquecido + agente template

Fase 1: Sistema de personalidades enriquecido
- Ampliar PersonalityCfg con role, backstory, expertise, limitations
- Añadir CommunicationCfg (formality, humor, personality, response_style, quirks, catchphrases)
- Crear tipos puros en pkg/personality/traits.go
- Implementar BuildPersonalityPrompt() para generar bloque de system prompt
- Integrar personalidad en agents/runtime.go (FromConfig + concatenacion al system prompt)

Fase 2: Agente plantilla
- Añadir campo Template bool a AgentMeta
- Filtrar agentes template en launcher (skip si template: true)
- Crear agents/_template/ con config.yaml completo y documentado
- Incluir TODAS las secciones (skills, shared_knowledge, schedules, security)
- agent.go minimo + prompts/system.md plantilla
- Actualizar dev-scripts/agent/new-agent.sh para copiar desde _template/

Fase 3: Ejemplos de personalidades
- Crear agents/_template/PERSONALITIES.md con 4 perfiles:
  * DevOps pragmatico
  * Analista meticuloso
  * Asistente amigable
  * Guardian de seguridad

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

agents/runtime.go

@@ -331,6 +331,7 @@ func New(cfg *config.AgentConfig, rules []decision.Rule, agentACL acl.ACL, logge
 	a := &Agent{
 		cfg:                  cfg,
 		acl:                  agentACL,
+		personality:          personality.FromConfig(cfg.Personality),
 		rules:                rules,
 		llm:                  llmFunc,
 		matrix:               matrixClient,
@@ -820,6 +821,21 @@ func (a *Agent) runLLM(ctx context.Context, msgCtx decision.MessageContext, memK
 
 	// Load system prompt from file if configured, else use description
 	systemPrompt := a.cfg.Agent.Description
+	if spFile := a.cfg.LLM.Reasoning.SystemPromptFile; spFile != "" {
+		// Resolve path relative to agent directory
+		spPath := filepath.Join("agents", a.cfg.Agent.ID, spFile)
+		if data, err := os.ReadFile(spPath); err == nil {
+			systemPrompt = string(data)
+		} else {
+			a.logger.Warn("failed to load system_prompt_file, using description", "path", spPath, "err", err)
+		}
+	}
+
+	// Concatenate personality prompt block
+	personalityBlock := personality.BuildPersonalityPrompt(a.personality)
+	if personalityBlock != "" {
+		systemPrompt = systemPrompt + "\n\n" + personalityBlock
+	}
 
 	// Build messages: conversation history from window (includes current user msg)
 	messages := a.getWindowMessages(memKey)