[C10] Abandoned near-duplicate `spike_*` / `modal_spike_*` scripts

[DsThakurRawat]

Labels: cleanup, tech-debt, priority:low
File: scripts/ — pairs spike_cuda_graphs_ort.py + modal_spike_cuda_graphs.py; spike_dual_instance_ort.py + modal_spike_dual_instance_ort.py; spike_vlm_prefix_diagnostic.py + modal_spike_vlm_prefix_diagnostic.py; orphan _spike_mmd_autocorrelation.py

Description. Stale exploratory spikes coexist in pairs, none referenced by CI, and mislead readers into thinking there are two supported code paths.

Tasks.

• Audit scripts/spike_* / modal_spike_*; delete or move superseded spikes to scripts/experiments/ with a README; dedupe the three pairs.

Dedup. #29 removes legacy export scripts specifically; this is the spike/duplicate cruft #29 doesn't cover. Distinct — reference #29.