feat(pos/workshop): add lightweight workshop/taller module

- Add DB migration v4.4_workshop.sql (sale_id, service_catalog,
  reserved_quantity, SO_RESERVE/SO_RELEASE operation types).
- Extend service_order_engine with inventory reservation, release,
  convert-to-sale, mechanic assignment, and service catalog CRUD.
- Extend service_order_bp with /reserve, /convert-to-sale,
  /assign-mechanic, and /service-catalog endpoints.
- Create workshop Kanban UI: workshop.html, workshop.js, workshop.css.
- Add /pos/workshop route and sidebar navigation (sidebar.js + inline
  templates).
- Add 11 unit tests with mocked cursors.
- Update FASES_IMPLEMENTADAS.md with FASE 9 documentation.

Tests: 92 passing (61 console + 20 Facturapi + 11 workshop).

pos/blueprints/service_order_bp.py

@@ -3,15 +3,31 @@
 Prefix: /pos/api/service-orders
 """
 
-from flask import Blueprint, request, jsonify, g
+from flask import Blueprint, g, jsonify, request
 from middleware import require_auth
-from tenant_db import get_tenant_conn
 from services.service_order_engine import (
-    create_service_order, get_service_order, list_service_orders,
-    update_status, add_item, update_item, remove_item,
-    add_labor, update_labor, remove_labor,
-    update_service_order, get_kanban_summary,
+    add_item,
+    add_labor,
+    assign_mechanic,
+    convert_to_sale,
+    create_service_catalog_item,
+    create_service_order,
+    delete_service_catalog_item,
+    get_kanban_summary,
+    get_service_order,
+    list_service_catalog,
+    list_service_orders,
+    release_item,
+    remove_item,
+    remove_labor,
+    reserve_item,
+    update_item,
+    update_labor,
+    update_service_catalog_item,
+    update_service_order,
+    update_status,
 )
+from tenant_db import get_tenant_conn
 
 service_order_bp = Blueprint('service_orders', __name__, url_prefix='/pos/api/service-orders')
 
@@ -202,3 +218,154 @@ def kanban_summary():
         return jsonify(summary)
     finally:
         conn.close()
+
+
+# ─── Inventory reservation ────────────────────────
+
+
+@service_order_bp.route('/<int:so_id>/items/<int:item_id>/reserve', methods=['POST'])
+@require_auth()
+def reserve_order_item(so_id, item_id):
+    """Reserve inventory for a service order item."""
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = reserve_item(conn, item_id, branch_id=g.branch_id, employee_id=g.employee_id)
+        return jsonify(result)
+    except ValueError as e:
+        return jsonify({'error': str(e)}), 400
+    finally:
+        conn.close()
+
+
+@service_order_bp.route('/<int:so_id>/items/<int:item_id>/release', methods=['POST'])
+@require_auth()
+def release_order_item(so_id, item_id):
+    """Release a previous inventory reservation."""
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = release_item(conn, item_id, employee_id=g.employee_id)
+        return jsonify(result)
+    except ValueError as e:
+        return jsonify({'error': str(e)}), 400
+    finally:
+        conn.close()
+
+
+# ─── Convert to sale ──────────────────────────────
+
+
+@service_order_bp.route('/<int:so_id>/convert-to-sale', methods=['POST'])
+@require_auth('pos.sell')
+def convert_order_to_sale(so_id):
+    """Convert a service order into a POS sale.
+
+    Body: {
+        payment_method: 'efectivo' | 'transferencia' | 'tarjeta' | 'mixto',
+        sale_type: 'cash' | 'credit' | 'mixed',
+        register_id: int (optional),
+        amount_paid: float (optional),
+        payment_details: [...] (optional),
+        notes: str (optional)
+    }
+    """
+    data = request.get_json() or {}
+    sale_payload = {
+        'payment_method': data.get('payment_method', 'efectivo'),
+        'sale_type': data.get('sale_type', 'cash'),
+        'register_id': data.get('register_id'),
+        'amount_paid': data.get('amount_paid'),
+        'payment_details': data.get('payment_details', []),
+        'notes': data.get('notes'),
+    }
+
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = convert_to_sale(
+            conn, so_id, sale_payload, employee_id=g.employee_id
+        )
+        return jsonify(result), 201
+    except ValueError as e:
+        return jsonify({'error': str(e)}), 400
+    finally:
+        conn.close()
+
+
+# ─── Mechanic assignment ──────────────────────────
+
+
+@service_order_bp.route('/<int:so_id>/assign-mechanic', methods=['PUT'])
+@require_auth()
+def assign_mechanic_endpoint(so_id):
+    """Assign a mechanic/technician to a service order."""
+    data = request.get_json() or {}
+    employee_id = data.get('employee_id')
+    if not employee_id:
+        return jsonify({'error': 'employee_id is required'}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = assign_mechanic(conn, so_id, employee_id)
+        return jsonify(result)
+    except ValueError as e:
+        return jsonify({'error': str(e)}), 400
+    finally:
+        conn.close()
+
+
+# ─── Service catalog (reusable labor) ─────────────
+
+
+@service_order_bp.route('/service-catalog', methods=['GET'])
+@require_auth()
+def list_catalog():
+    """List reusable labor/service concepts."""
+    active_only = request.args.get('active_only', 'true').lower() != 'false'
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        items = list_service_catalog(conn, active_only=active_only)
+        return jsonify({'data': items})
+    finally:
+        conn.close()
+
+
+@service_order_bp.route('/service-catalog', methods=['POST'])
+@require_auth()
+def create_catalog_item():
+    """Create a reusable labor concept."""
+    data = request.get_json() or {}
+    if not data.get('name'):
+        return jsonify({'error': 'name is required'}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = create_service_catalog_item(conn, g.tenant_id, data)
+        return jsonify(result), 201
+    finally:
+        conn.close()
+
+
+@service_order_bp.route('/service-catalog/<int:item_id>', methods=['PUT'])
+@require_auth()
+def update_catalog_item(item_id):
+    """Update a reusable labor concept."""
+    data = request.get_json() or {}
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        ok = update_service_catalog_item(conn, item_id, data)
+        if not ok:
+            return jsonify({'error': 'No fields to update'}), 400
+        return jsonify({'message': 'Catalog item updated'})
+    finally:
+        conn.close()
+
+
+@service_order_bp.route('/service-catalog/<int:item_id>', methods=['DELETE'])
+@require_auth()
+def delete_catalog_item(item_id):
+    """Soft-delete a reusable labor concept."""
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        delete_service_catalog_item(conn, item_id)
+        return jsonify({'message': 'Catalog item deactivated'})
+    finally:
+        conn.close()