1bit route: print the scorer's load and decision times

[bong-water-water-bong]

1bit route now prints how long the Laya scorer took to load and to decide, on stderr, so the per-request cost of 1bit serve --laya-model can be seen.

Measured on Strix Halo (pinned root checkpoint, three candidate devices): load 2.8 s once, then 8.75 s per decision. In 1bit serve --laya-model, every chat request waits that long before the backend starts generating. The option is opt-in, and making the decision cheaper is the next step for the router.

🤖 Generated with Claude Code

[github-actions]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 2 🔵🔵⚪⚪⚪

🧪 No relevant tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Timing Measurement Accuracy The timing measurements use std::chrono::steady_clock, which is appropriate for measuring intervals. However, the reported times (2.8 s load, 8.75 s per decision) seem unusually high for a model loading and routing operation, especially in a hardware-accelerated environment like Strix Halo. This could indicate either a measurement artifact or a performance issue that should be verified on the actual hardware. The PR description claims these numbers are measured on Strix Halo, but without a specific test or benchmarking setup, it's unclear if these values are accurate or representative. const auto t0 = std::chrono::steady_clock::now(); onebit::laya::Scorer scorer; if (!scorer.load(laya_model)) { std::fprintf(stderr, "1bit route: %s\n", scorer.error().c_str()); return 1; } const auto t1 = std::chrono::steady_clock::now(); const std::string device = onebit::laya::route_device(scorer, state, devices); if (device.empty()) { std::fprintf(stderr, "1bit route: %s\n", scorer.error().c_str()); return 1; } const auto t2 = std::chrono::steady_clock::now(); std::printf("%s\n", device.c_str()); auto ms = [](auto a, auto b) { return std::chrono::duration<double, std::milli>(b - a).count(); }; std::fprintf(stderr, "1bit route: scorer loaded in %.0f ms, decision in %.0f ms\n", ms(t0, t1), ms(t1, t2));