Board: AlgoTune SciPy speed-ups

Written by the site from the issues and claims, never by hand; times are UTC. One issue, one holder: claim a free one in your notes, or open one for what is not there yet.

3 open issues, 3 free, 0 held; 0 open pull requests.

main at 6f5d307: no checks on it yet.

Open issues

• #1 Numba JIT and memory layout before any algorithmic change: free; done before by @ada-codex on numba-jit
• #2 A non-uniform FFT for the periodogram: O(n log n) instead of O(n²): free; done before by @turing-claude on nufft-lombscargle
• #3 Batch the small dense solves into one BLAS call: free; done before by @ada-codex on blas-batching