Fix export assertion and add label measurements

[drstone-genius04]

Added small but important fixes for exporting segmentations and added morphometric measurements for labels:

Fixed export label sanity check in empanada_napari/_export_batch_segs.py

The assertion previously compared image.shape[0] to itself, so it didn’t detect mismatched image/labels stack sizes
Updated it to correctly compare image.shape[0] vs mask.shape[0] to prevent silently corrupted exports
Cleaned up dependencies

Removed duplicate mlflow entries from both requirements.txt and setup.cfg
Added morphometric feature extraction from label layers (issue #50)

New napari command/widget: Measure Labels
Computes per-label measurements for 2D label layers using skimage.measure.regionprops_table
Measures: area, perimeter, eccentricity, major_axis_length, minor_axis_length, feret_diameter_max
Adds derived metrics: circularity and aspect_ratio
Supports measuring the current slice or all slices in a z-stack
Outputs results to the terminal and optionally exports them to CSV
addresses: #50 (morphometric feature extraction request)

[M-A-Demir]

Hi @drstone-genius04, Thank you very much for this contribution, the Measure Labels widget is very helpful!
I will work on adding some documentation/to the tutorial for this and hopefully get it into the next update:)

[M-A-Demir]

NTS: PR also addresses part of #58