Dev bench (not a test, not in the gate suite): mounts <App> under the Solid test renderer, pushes N streamed turns, samples RSS + mounted-renderable count with Bun.gc. Demonstrates HERMES_TUI_MAX_MESSAGES=400 pins mounted renderables at ~2218 vs an unbounded climb to ~55k at 10k messages (RSS flat ~350MB vs 1.3GB). Run: bun scripts/mem-bench.tsx (MEM_BENCH_TOTAL/SAMPLE tunable).