Avoid repeating the exponential search for odd orders at least nine. Search the even predecessor, translate its row-major placements to the enlarged board, and tile the new border.
Keep direct search and construction explicit so benchmarks can report their costs separately. Verify the routed order-9 result independently and require its search counters to match order 8.
Tests: Release, Debug, ASan and UBSan CTest (8 passed each)
Refs: #6
Record reproducible order-7 and order-8 measurements from the committed benchmark framework with a clean working tree. Include stable work counts, solve-time spread, validation and rendering cost, and interleaved instrumentation overhead.
Order 9 remains supported by the runner but retains its historical timing because each current run takes several minutes.
Benchmark: Apple arm64 Release, one warm-up, three repetitions
Refs: #8
Add an opt-in benchmark probe and JSON runner that separate solve, construction, validation, and rendering time. Record stable search counters, environment metadata, warm-up and repetition policy, timeouts, errors, median spread, and instrumentation overhead.
Compile production solving without counters and interleave counted and plain trials when measuring overhead. Keep heavyweight cases outside the default correctness path while testing counter and report behavior cheaply.
Tests: Debug and Release CTest suites (7 passed each)
Refs: #8
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