[Copilot]

Adds a configurable minimum face bounding-box size filter to the Python face-recognition service. Faces whose longest side (width or height, in pixels) does not strictly exceed the threshold are discarded before the Laplacian/blur check runs.

Changes

app/config.py

• New min_face_size_pixels: int = 0 setting (VISION_FACE_MIN_FACE_SIZE_PIXELS env var). 0 = disabled (default, no behaviour change).
• Included in to_diagnostics_payload() → appears in GET /config response and the AiVisionServiceConfigCheck PHP diagnostic pipe.

app/detection/detector.py

• New min_face_size_pixels constructor param on FaceDetector.
• Size filter inserted between the confidence check and the Laplacian computation:

  if self._min_face_size_pixels > 0:
      longest_side = max(float(area["w"]), float(area["h"]))
      if longest_side <= self._min_face_size_pixels:
          filtered_by_size += 1
          continue   # dropped before any blur computation

• Filter summary log extended with filtered_by_size count.

app/main.py

• Passes min_face_size_pixels=settings.min_face_size_pixels to FaceDetector.

tests/test_detection.py

• 5 new test cases: filter by width, filter by height, pass when above threshold, no-op when zero, and ordering assertion (size filter fires before blur filter).