Lamp testbench in Rust around the HPCS 6500

lampbench station / export / label / tm30 / calibrate replace the Python
lamp_station.py, lamp_export.py, label_printer.py, tm30.py and
calibration.py that lived in HPCS6500-py. The driver is a submodule
(HPCS6500/, like mppt-testbench). Workspace crates: tm30 (TM-30-18 port of
colour-science 0.4.7), brother-ql (raster protocol, byte-identical to
brother_ql) and lamp-label (QR + ID labels for the QL-820NWB).

Bundles are byte-identical to lamp_export.py's (golden tests); the station
runs end to end in a test against the simulated instrument.

tests/golden/bundles/cases.json

@@ -0,0 +1,89 @@
+{
+ "measured_at": "2026-07-09T16:22:57+07:00",
+ "cases": [
+  {
+   "case": "export_avg5",
+   "readings": [
+    "r01",
+    "r04",
+    "r05",
+    "r06",
+    "r02"
+   ],
+   "meta": {
+    "name": "philips-a60",
+    "manufacturer": "Philips",
+    "model": "A60 8W 927",
+    "notes": ""
+   },
+   "supply": null
+  },
+  {
+   "case": "station_full",
+   "readings": [
+    "r05",
+    "r06",
+    "r04"
+   ],
+   "meta": {
+    "name": "L0042",
+    "ean": "8718696844984",
+    "type": "led",
+    "dimmable": false,
+    "variant": "cool white",
+    "manufacturer": "Philips",
+    "model": "MyCare 9.5W Caf\u00e9 \u00fc \u0e44\u0e1f",
+    "notes": "box says \"warm\"\tok",
+    "rated": {
+     "Phi_lm": 1050,
+     "Power_W": 9.5,
+     "lifetime_h": 15000
+    }
+   },
+   "supply": {
+    "ac_voltage": 230.0,
+    "ac_frequency": 50.0,
+    "dc_voltage": 24.0,
+    "dc_current": 5.0,
+    "mode": "AC"
+   }
+  },
+  {
+   "case": "harmonics_single",
+   "readings": [
+    "r02"
+   ],
+   "meta": {
+    "name": "L0007",
+    "ean": "",
+    "type": "halogen",
+    "dimmable": true,
+    "variant": "",
+    "manufacturer": "",
+    "model": "",
+    "notes": "",
+    "rated": {}
+   },
+   "supply": {
+    "ac_voltage": 230.0,
+    "ac_frequency": 50.0,
+    "dc_voltage": 24.0,
+    "dc_current": 5.0,
+    "mode": "AC"
+   }
+  },
+  {
+   "case": "external_power",
+   "readings": [
+    "r07"
+   ],
+   "meta": {
+    "name": "dc-strip",
+    "manufacturer": "",
+    "model": "",
+    "notes": "powered externally"
+   },
+   "supply": null
+  }
+ ]
+}