Establish a CTest harness before changing solver behavior. Validate board dimensions, multiplicities, bounds, overlap and coverage against independent placement data, including known order-8 and constructed order-9 fixtures.
Document Debug and sanitizer workflows while keeping the defects tracked by #7 and #14 separate. Prepare a result adapter so the feasible solver regression can be enabled with the completion fix.
Tests: Release, ASan and UBSan CTest suites (3 passed each)
Refs: #1
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