Rewrite the driver in Rust; move the testbench tools out

The repository is now only the HPCS 6500 driver: a Rust library (serial
transport, every protocol command, block parsing, USBPcap captures, a
simulated instrument) and the hpcs6500 CLI with the flags of the former
hpcs6500.py, plus dump/capture for reverse engineering.

The lamp station, lamp export, TM-30, label printer and LED calibration
move to B4L/lamp-testbench. Golden tests pin the Rust output to the Python
driver's: parsed values bit-exact, report text, CSV and number formatting.
The Python driver is at tag python-final.

tests/golden/parse_usb_capture_20260204_123655_hub1.txt

@@ -0,0 +1,90 @@
+
+============================================================
+Reading 1 (t=0.01s)
+============================================================
+  Device: HPCS6500
+  Date: 2026-02-04  Time: 15:58:55
+
+  --- Photometric ---
+  Phi (lm):          479.98
+  eta (lm/W):         57.09
+  CCT (K):             5653
+  Duv:              0.00551
+
+  --- Chromaticity ---
+  x:   0.3289    y:  0.3488
+  u:   0.2015    v:  0.3206
+  u':  0.2015    v': 0.4809
+
+  --- CRI ---
+  Ra:  83.0    SDCM: 4.69
+  R1=82, R2=94, R3=93, R4=77, R5=82, R6=89, R7=83, R8=64
+  R9=5, R10=84, R11=76, R12=60, R13=87, R14=97, R15=76
+
+  --- CIE 1931 ---
+  X: 662.526  Y: 702.748  Z: 649.286
+  TLCI-2012: 68
+
+  --- Radiometric ---
+  Phi_e (mW):      1492.631
+  Phi_eb (mW):      470.398
+  Phi_ey (mW):      680.493
+  Phi_er (mW):      331.425
+  Phi_efr (mW):      11.458
+
+  --- Electrical ---
+  Voltage (V):       230.31
+  Current (A):       0.0653
+  Power (W):          8.407
+  Frequency (Hz):     50.02
+  Power Factor:      0.5591
+
+  --- Sensor ---
+  Peak Signal:        53066
+  Dark Signal:         2219
+  Compensate:          2834
+
+============================================================
+Reading 2 (t=2.13s)
+============================================================
+  Device: HPCS6500
+  Date: 2026-02-04  Time: 16:02:06
+
+  --- Photometric ---
+  Phi (lm):          479.89
+  eta (lm/W):         57.09
+  CCT (K):             5655
+  Duv:              0.00550
+
+  --- Chromaticity ---
+  x:   0.3288    y:  0.3488
+  u:   0.2015    v:  0.3206
+  u':  0.2015    v': 0.4809
+
+  --- CRI ---
+  Ra:  83.0    SDCM: 4.67
+  R1=82, R2=94, R3=93, R4=77, R5=82, R6=89, R7=83, R8=64
+  R9=5, R10=84, R11=76, R12=60, R13=86, R14=97, R15=76
+
+  --- CIE 1931 ---
+  X: 662.427  Y: 702.620  Z: 649.490
+  TLCI-2012: 68
+
+  --- Radiometric ---
+  Phi_e (mW):      1492.469
+  Phi_eb (mW):      470.073
+  Phi_ey (mW):      679.697
+  Phi_er (mW):      330.648
+  Phi_efr (mW):      11.237
+
+  --- Electrical ---
+  Voltage (V):       230.30
+  Current (A):       0.0653
+  Power (W):          8.406
+  Frequency (Hz):     50.02
+  Power Factor:      0.5592
+
+  --- Sensor ---
+  Peak Signal:        53055
+  Dark Signal:         2246
+  Compensate:          2834