Two blockers discovered while running ADR-079 P7→P8 end-to-end against
a 30-minute paired session (39,088 GT frames + 45,625 CSI frames):
1. `readFileSync(_, 'utf8').split('\n')` hit Node's `String.MaxLength`
(~512 MB) on the 750 MB CSI recording. Result:
Error: Cannot create a string longer than 0x1fffffe8 characters
Replaced loadJsonl with a 1 MiB byte-buffer streaming reader that
decodes line-by-line, so memory use stays bounded by the largest
single record.
2. The sensing-server has long since switched from the legacy `raw_csi`
/ `feature` typed records to a single `sensing_update` record per
tick (with nodes[].amplitude and top-level features). The aligner
filtered on the old types and produced 0 frames every time. Added a
`sensing_update` branch that projects each tick into rawCsi/features
entries the existing windowing code can consume, and updated
extractCsiMatrix to use already-extracted amplitudes when iqHex is
absent. timestamp is now accepted as either ISO string (legacy) or
numeric float-seconds (current).
End-to-end verified: produces 1,077 paired samples at
`--min-confidence 0.3 --window-frames 20` from the full 30-min
recording; downstream `train-wiflow-supervised.js` runs to completion.
See follow-up #640 for the PCK gap (data + GPU needed) — those are
training concerns, not aligner concerns.
rUv