refactor: complete bootstrap of ARNES agent harness framework

- Add complete agent harness structure with 8 roles (leader, triager, architect, implementer, reviewer, security, qa, documenter)
- Implement strict workflow with 9 stages and mandatory gates
- Add comprehensive verification script and runtime status tracking
- Create artifact-based evidence system with contracts and schemas
- Add agent policy matrix with permissions and anti-cheat rules
- Include test suite (44 tests passing) and CI-ready structure
- Add documentation: README, HOWTO, CHECKPOINTS, templates
- Configure model routing policies and token-aware task assignment
- Add BDD/SDD specification guides and feature templates
- Include starter pack for quick project onboarding

All verification checks pass. Framework ready for production use.

spec/sdd/README.md

@@ -0,0 +1,67 @@
+# SDD — System Design Document
+
+## Índice
+
+- [Architecture Overview](#architecture-overview)
+- [Components](#components)
+- [Decisions](#decisions)
+
+---
+
+## Architecture Overview
+
+```mermaid
+graph TD
+    subgraph Frontend
+        F[Client App]
+    end
+    
+    subgraph Backend
+        A[API Gateway]
+        S[Services]
+        D[(Database)]
+    end
+    
+    F --> A
+    A --> S
+    S --> D
+```
+
+### Contexto
+_Describir el propósito del sistema y su alcance._
+
+### Restricciones
+- _Lista de restricciones técnicas o de negocio_
+
+---
+
+## Components
+
+### Component Template
+
+Ver `spec/sdd/components/.template.md` para el formato.
+
+---
+
+## Decisions
+
+Ver `spec/sdd/decisions/` para ADRs.
+
+---
+
+## Diagrama de secuencia (ejemplo)
+
+```mermaid
+sequenceDiagram
+    actor U as User
+    participant API
+    participant SVC as Service
+    participant DB as Database
+    
+    U->>API: Request
+    API->>SVC: Process
+    SVC->>DB: Query
+    DB-->>SVC: Result
+    SVC-->>API: Response
+    API-->>U: Data
+```