Query parameter 'format' shadows Python built-in

[jtdub]

Problem

In reports.py:67, the export endpoint uses format as a query parameter name:

async def export_report(report_id: str, format: str = Query("json")) -> str:

This shadows Python's built-in format() function within the function scope.

Suggested Fix

Rename the parameter to format_type or export_format, using FastAPI's Query(alias="format") to preserve the external API:

async def export_report(report_id: str, export_format: str = Query("json", alias="format")) -> str: