feat(infra): conexion y consulta directa a SQL Server (Navision) via pymssql

Grupo de capacidad nuevo 'sql-connect' (3 funciones) para conectar a un
Microsoft SQL Server (donde corre Navision) y consultar directamente, en
lugar del ida y vuelta manual de pegar CSVs.

- mssql_connect_py_infra: abre conexion pymssql (login_timeout acotado,
  credenciales por argumento, RuntimeError claro si falla).
- mssql_query_py_infra: SELECT parametrizada con binding seguro (sin
  inyeccion) sobre conexion abierta; devuelve {columns, rows, row_count};
  0 filas -> lista vacia; max_rows con fetchmany; read-only.
- run_mssql_query_py_pipelines: one-shot que compone connect+query y cierra
  siempre; CLI imprime JSON o CSV; contrasena desde env var (pass).

Pagina madre docs/capabilities/sql-connect.md + fila en INDEX.md.
Dependencia pymssql>=2.3.13 anadida a python/pyproject.toml + uv.lock.
Tests mock-based (11) verdes; error path verificado end-to-end contra el
driver real (host inalcanzable -> RuntimeError, acotado por login_timeout).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

python/functions/infra/mssql_connect_test.py

@@ -0,0 +1,59 @@
+"""Tests for mssql_connect (mock-based, no real SQL Server)."""
+
+from __future__ import annotations
+
+import os
+import sys
+
+import pytest
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+from mssql_connect import mssql_connect
+
+
+def test_golden_connect_passes_string_port_and_kwargs(monkeypatch):
+    """Golden path: returns the driver connection and forwards the right kwargs.
+
+    The TCP port must reach pymssql as a STRING, and login_timeout must default
+    to 15 when not supplied.
+    """
+    captured: dict = {}
+    sentinel = object()
+
+    def fake_connect(**kwargs):
+        captured.update(kwargs)
+        return sentinel
+
+    monkeypatch.setattr("pymssql.connect", fake_connect)
+
+    result = mssql_connect("10.0.0.5", "navdb", "sa", "pw", port=1433)
+
+    assert result is sentinel
+    assert captured["server"] == "10.0.0.5"
+    assert captured["database"] == "navdb"
+    assert captured["user"] == "sa"
+    assert captured["password"] == "pw"
+    assert captured["port"] == "1433"
+    assert isinstance(captured["port"], str)
+    assert captured["login_timeout"] == 15
+    assert captured["timeout"] == 30
+
+
+def test_error_path_wraps_failure_with_host(monkeypatch):
+    """Error path: a driver failure becomes a clear RuntimeError, not a hang.
+
+    The wrapped message must include the host and the phrase 'failed connecting'
+    so callers can diagnose connectivity problems.
+    """
+    def fake_connect(**kwargs):
+        raise Exception("login timeout")
+
+    monkeypatch.setattr("pymssql.connect", fake_connect)
+
+    with pytest.raises(RuntimeError) as excinfo:
+        mssql_connect("10.0.0.5", "navdb", "sa", "pw", port=1433)
+
+    message = str(excinfo.value)
+    assert "10.0.0.5" in message
+    assert "failed connecting" in message