Add compare_weights: order-agnostic weights file comparison (6)

[cattabiani]

Fix: #88
Fix: #85

Adds a public compare_weights function and CLI command for order-agnostic comparison of weights H5 files.

Changes

• bluerecording/compare.py — compare_weights(reference, target, rtol, atol, population_name) returns (bool, report_str)
• CLI — bluerecording compare_weights ref.h5 new.h5 --rtol 1e-6 --atol 1e-9 (exit 0 = match, 1 = mismatch)
• Refactored integration tests — replaced 5 duplicated _get_node_scaling_factors helpers with one compare_weights call each
• Unit tests — matching, order-agnostic matching, mismatched values, mismatched node_ids

Usage

Python:

from bluerecording import compare_weights

match, report = compare_weights("reference.h5", "new.h5")
print(report)

CLI:

bluerecording compare_weights reference.h5 new.h5