feat: configuracion de skills en schema

Agregar SkillsCfg y SkillsToolCfg al config schema:

SkillsCfg (nivel agente):
- enabled: activar/desactivar skills
- path: directorio de skills (default: skills/)
- categories: filtro de categorias a cargar
- timeout: timeout de ejecucion de scripts

SkillsToolCfg (nivel tools):
- allowed_interpreters: allowlist de interpreters (bash, python3, etc.)

Permite configurar skills por agente de forma granular.

internal/config/schema.go

@@ -18,6 +18,7 @@ type AgentConfig struct {
 	Resilience  ResilienceCfg  `yaml:"resilience"`
 	Storage     StorageCfg     `yaml:"storage"`
 	Memory      MemoryCfg      `yaml:"memory"`
+	Skills      SkillsCfg      `yaml:"skills"`
 }
 
 // ── Identity ──────────────────────────────────────────────────────────────
@@ -130,6 +131,7 @@ type ToolsCfg struct {
 	Memory          MemoryToolCfg          `yaml:"memory"`
 	Knowledge       KnowledgeToolCfg       `yaml:"knowledge"`
 	SharedKnowledge SharedKnowledgeToolCfg `yaml:"shared_knowledge"`
+	Skills          SkillsToolCfg          `yaml:"skills"`
 }
 
 type MatrixToolCfg struct {
@@ -478,6 +480,19 @@ type MemoryToolCfg struct {
 	Enabled bool `yaml:"enabled"`
 }
 
+// ── Skills ────────────────────────────────────────────────────────────────
+
+type SkillsCfg struct {
+	Enabled    bool     `yaml:"enabled"`     // enable skills system (default false)
+	SkillsPath string   `yaml:"path"`        // path to skills directory (default: "skills/")
+	Categories []string `yaml:"categories"`  // filter: only load skills from these categories (empty = all)
+	Timeout    time.Duration `yaml:"timeout"` // timeout for script execution (default: 60s)
+}
+
+type SkillsToolCfg struct {
+	AllowedInterpreters []string `yaml:"allowed_interpreters"` // allowlist for skill script execution (default: ["bash", "sh"])
+}
+
 // ── Special Agents ────────────────────────────────────────────────────────
 
 // SpecialConfig is the root configuration for a special agent (no Matrix identity).