fix: NVCM programmed check reads STATUS Done bit, not the auto-boot test

[boringethan]

Refs #44

Root cause

_interpret_nvcm_blob (motion_connector.py:551 on next) derived its verdict from the auto-boot test bytes of the OW_FACTORY_NVCM_CHECK blob: boot_0x40_responds == 0 → PROGRAMMED. That signal is unconditionally "programmed": the CrossLink I2C slave config port at 0x40 only becomes active after receiving the activation key, so after a key-less CRESETB release it never ACKs regardless of NVCM state. Every camera with a valid IDCODE therefore reported PROGRAMMED — blank parts included.

This is the exact trap sensor-fw already hit and fixed in its own runtime detector (openmotion-sensor-fw commit c40a6b4, "fix(nvcm): rewrite fpga_detect_nvcm to use Done bit instead of boot test" — hardware-verified there). The app's interpreter was ported from the stale scripts/nvcm_probe.py verdict logic that predates that finding.

Fix

• New utils/nvcm_verdict.py (pure, Qt-free): verdict now comes from the STATUS register Done bit (bit 8 → blob[8] bit 0, big-endian status bytes), which the blob already carries. The Done fuse is the last step burned during NVCM programming and is what gates auto-boot: Done=1 → PROGRAMMED, Done=0 → BLANK. A failed STATUS read or IDCODE mismatch → INCONCLUSIVE. Detail strings now include the raw STATUS bytes.
• _NvcmCheckThread passes boot_test=False — the boot probe carries no information and just adds CRESETB cycling per camera.
• tests/test_nvcm_verdict.py: 16 unit cases, including a regression case built from the real blank-camera blob recorded in the sensor-fw NVCM notebook (STATUS 00 00 02 08, boot test claiming "0x40 gone") — old code returned PROGRAMMED for it, new code returns BLANK — and a sweep proving the verdict is independent of the boot-test bytes.

Companion SDK PR fixing the same verdict logic in the reference script: OpenwaterHealth/openmotion-sdk#118.

Hand-test

On a sensor with known-blank NVCM cameras (e.g. the left module verified all-blank in sensor-fw c40a6b4, minus any cameras burned since):

1. Sensors page → Check NVCM (all).
2. Blank cameras must now report BLANK — STATUS Done bit clear (status 00 00 02 08) (previously: PROGRAMMED).
3. An NVCM-burned camera (e.g. the camera burned via the Flash button + Done-fuse retry) must report PROGRAMMED — STATUS Done bit set.
4. Unpowered/absent camera slots → NO RESPONSE / INCONCLUSIVE, not PROGRAMMED.
5. Header line "All 8 cameras PROGRAMMED" should only appear when every camera is Done=1.

Note (pre-existing behavior): the check forces the FPGAs into config mode, so checked cameras need an FPGA reprogram / power-cycle before normal streaming.

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