Connectivity peakmem benchmarks - #1661

Closes #1660

Overview

Two sets of memory benchmarks, tracking allocations in isolation and total peakmem usage.

PR Checklist

General

• An issue is created and linked
• Added appropriate labels (if your uxarray repo permissions allow it)
• Filled out Overview and Expected Usage (if applicable) sections

Testing & Benchmarking

• Adequate tests are created if there is new functionality
• Tests are not too basic (such as simply calling a function and nothing else)
• Tests cover all major paths in your new functions
• If this PR could affect performance, ran ASV benchmarks and confirmed they show expected behavior (add a new benchmark if necessary)

Documentation

• Docstrings have been added to all new functions
• Docstrings have been updated with any function changes

AI Disclosure

AI Usage: Claude Opus 5

• I take responsibility for all AI-generated content in my PR.
• I have tested all AI-generated content in my PR.