feat: add BigQuery Python functions and BQClient type

Funciones CRUD completas para BigQuery: auth, datasets, tables, queries,
jobs, routines, load/export. Tipo BQClient como wrapper del SDK oficial.

python/functions/bigquery/jobs.py

@@ -0,0 +1,105 @@
+"""Gestion de jobs en Google BigQuery."""
+
+from .client import BQClient
+
+
+def bq_list_jobs(
+    client: BQClient,
+    state_filter: str = "",
+    max_results: int = 50,
+    all_users: bool = False,
+) -> list[dict]:
+    """Lista jobs del proyecto con filtro opcional por estado.
+
+    Args:
+        client: Cliente autenticado.
+        state_filter: Filtro: "running", "pending", "done". Vacio = todos.
+        max_results: Numero maximo de jobs a retornar.
+        all_users: Si True, lista jobs de todos los usuarios (requiere permisos).
+
+    Returns:
+        Lista de dicts con: job_id, job_type, state, created, started, ended,
+        user_email, bytes_processed, error.
+
+    Example:
+        >>> jobs = bq_list_jobs(client, state_filter="running")
+        >>> for j in jobs:
+        ...     print(j["job_id"], j["state"], j["job_type"])
+    """
+    kwargs = {"max_results": max_results, "all_users": all_users}
+    if state_filter:
+        kwargs["state_filter"] = state_filter
+    return [_job_to_dict(job) for job in client._client.list_jobs(**kwargs)]
+
+
+def bq_get_job(client: BQClient, job_id: str) -> dict:
+    """Obtiene detalles de un job por su ID.
+
+    Args:
+        client: Cliente autenticado.
+        job_id: ID del job.
+
+    Returns:
+        Dict con: job_id, job_type, state, created, started, ended,
+        user_email, bytes_processed, destination_table, query, error, errors.
+
+    Raises:
+        google.api_core.exceptions.NotFound: Si el job no existe.
+
+    Example:
+        >>> job = bq_get_job(client, "job_abc123")
+        >>> print(job["state"], job["bytes_processed"])
+        >>> if job["error"]:
+        ...     print("Error:", job["error"])
+    """
+    job = client._client.get_job(job_id)
+    result = _job_to_dict(job)
+    # Agregar detalles extra disponibles en get pero no en list
+    if hasattr(job, 'destination') and job.destination:
+        result["destination_table"] = str(job.destination)
+    if hasattr(job, 'query') and job.query:
+        result["query"] = job.query
+    if job.errors:
+        result["errors"] = [dict(e) for e in job.errors]
+    return result
+
+
+def bq_cancel_job(client: BQClient, job_id: str) -> dict:
+    """Cancela un job en ejecucion.
+
+    Args:
+        client: Cliente autenticado.
+        job_id: ID del job a cancelar.
+
+    Returns:
+        Dict con: job_id, state (tras cancelacion).
+
+    Raises:
+        google.api_core.exceptions.NotFound: Si el job no existe.
+
+    Example:
+        >>> result = bq_cancel_job(client, "job_abc123")
+        >>> print(result["state"])  # "DONE" (cancelled)
+    """
+    job = client._client.cancel_job(job_id)
+    return {"job_id": job.job_id, "state": job.state}
+
+
+def _job_to_dict(job) -> dict:
+    """Convierte un objeto Job del SDK a dict plano."""
+    result = {
+        "job_id": job.job_id,
+        "job_type": job.job_type,
+        "state": job.state,
+        "created": job.created.isoformat() if job.created else None,
+        "started": job.started.isoformat() if job.started else None,
+        "ended": job.ended.isoformat() if job.ended else None,
+        "user_email": job.user_email,
+        "error": str(job.error_result) if job.error_result else None,
+    }
+    # bytes_processed solo disponible en query jobs
+    try:
+        result["bytes_processed"] = job.total_bytes_processed
+    except AttributeError:
+        result["bytes_processed"] = None
+    return result