[ryanbr]

Reworks the #592 probe output after the capture confirmed opcode 98 returns a rich 29-byte payload on the 4.0. Two things: make the result readable/copyable, and make multiple captures do the field-mapping (one frame can't, responsibly).

Cleaner output

A pure, unit-tested formatExtendedBatteryProbe renders the result as a clean report instead of a dense run-on. Your capture now reads:

#592 EXTENDED-BATTERY PROBE — WHOOP 4.0
Verdict: opcode 98 ACCEPTED — 29-byte payload

Raw frame (40 B):
aa2400fa24c6620d010165006bff820f0c0128000f05e90321120200010100001a0000004675fe58

Payload (29 B, CRC excluded):
  @00  0d 01 01 65 00 6b ff 82
  @08  0f 0c 01 28 00 0f 05 e9
  @16  03 21 12 02 00 01 01 00
  @24  00 1a 00 00 00

Voltage: 3.97 V  (mV=3970 @07) — the field NOOP already reads

Δ vs previous capture: first capture — probe again at another battery % to diff

Full raw hex stays on one line (copies cleanly); the payload is an offset-labelled hex grid; the voltage is decoded inline.

Field-mapping scaffold

Persists each payload (SharedPreferences, so captures hours/days apart still diff) and, on the next probe, shows a per-byte delta. The layout can't be read off a single frame — the fields are identified by what they track: capture at 60% and 40% → the byte(s) that moved are SoC/capacity; cold vs worn → the byte that drifted is temperature; a byte that only ever climbs is cycle count.

Tests

ExtendedBatteryProbeFormatTest pins it against the real 4.0 capture (98 accepted, mV=3970 → 3.97 V, hex grid, first-capture), the diff (a moved byte is flagged with its offset), a bare stub, and a 5/MG UNSUPPORTED(3) verdict — 4 cases, all JVM-pure.

Verification

• Full Android module compiles; testFullDebugUnitTest green; i18n_audit.py --ci main exit 0; byte-scan confirms no stray control chars.
• Read-only, additive; no new opcode, no automatic sends. Swift twin to follow with the probe twin.

Companion to #603 (surfaces the confirmed voltage on the Devices card now).