Add benchmark comparison chart to README

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Henry Barnes

README.md

@@ -21,6 +21,8 @@ All results are reproducible. Clone, install, train, deploy.
 
 *Italicized targets are in progress. See `results.json` for machine-readable results.*
 
+![Benchmark Comparison](figures/benchmark_comparison.png)
+
 ## Competitive Context
 
 | Benchmark | Catalyst | Loihi 1 | Loihi 2 | Akida 2 | SpiNNaker 2 |