Add strip endpoint backed by an ExifTool process pool - #1

The reviewed changes passed unit and real-ExifTool integration tests, and I found no actionable defects.

Adds a /strip endpoint backed by a warmed ExifTool process pool, with bounded uploads, request limits, deadlines, and strip telemetry. The service strips metadata while preserving orientation and ICC profiles, and includes unit and real-ExifTool coverage for the supported image formats. The newest changes stream uploads and responses through temporary files and expand format coverage and pool-size metrics.