Demonstrates why process isolation beats free-threaded Python for image work.

Generates 30 test images (up to 4K resolution) in Python via Pillow, then creates thumbnails using the WeightedBatch strategy where batch boundaries are determined by total pixel count. After processing, collects per-worker memory statistics to show that Slither's backpressure kept peak memory bounded.

Why This Exists

Under free-threaded Python (PEP 703):

• Pillow's C internals (libImaging) are not thread-safe; concurrent Image.resize(LANCZOS) can produce corrupted output or segfault
• No built-in backpressure means 16 threads each loading a 4K image = 500MB+ memory spike
• One thread's segfault kills ALL threads

Under Slither:

• WeightedBatch groups images by pixel count so large images get their own batch
• max_in_flight: 2 caps concurrent batches (backpressure)
• Each Python worker is a separate OS process, so Pillow is safe
• A crash in one worker does not affect others

Run with:

Slither.Examples.ImagePipeline.ThumbnailDemo.run_demo()