Migrate the specs worth keeping from playground/tests/e2e (retired in P1) into
manifold/tests/e2e, adapted to Manifold's probe surface:
- probe-api.spec.ts: the window.__nisps debug-probe contract (ready, bounded
outputs, example count, randomise, setInputs inference, thumbsUp/Down,
addExample, train loss non-increasing, async train, clearExamples, evalLoss,
inferBatch, getLayerStats, getWeights). Retargeted to MLP<32,10,14,18,126>
(weight_count 3148) and Manifold's direct addExample/routedOutputs surface;
dropped the playground's __init/iml-poke escape hatches and stream-pending
skips.
- spine.spec.ts: the spine invariant — setInputs -> processed -> ml -> routed
yields bounded, consistent routed outputs; the probe stays alive across dock
output-mode switches (driven via the real selector UI, replacing the
playground's localStorage-reload mode cycling).
- helpers.ts: loadProbe(?debug=1 + cleared storage + __ready wait), settleInputs
for EMA convergence, bounded/changed assertions.
Dropped playground UI specs (ui-interactions, persistence, mode-registry list)
that die with the playground chrome. No probe.ts changes needed.
