Add the Sillitoe SDMS as a second mastering lathe candidate

Sillitoe Audio Technology (Australia) sells a complete cutting system:
lathe, MMFB feedback cutterhead, cutting amplifier, Space / Time Control
automation with a virtual groove, vacuum and microscope, at a published
USD 125,000 ex tax and shipping. Vendor landscape gets the narrative and
an Agnew-or-Sillitoe comparison; supplier map, total investment basis,
roadmap item 13 and the digital factory's no-telemetry section (STC cue
sheet, Open Groove export, stylus hours) follow.

docs/digital-factory.md

@@ -441,11 +441,21 @@ production data.
 
 ### What produces no telemetry
 
-The Agnew lathe and mastering chain, the Sibert stamper-prep machines and
-the shrink wrapper produce no machine data. They get station check-ins:
-who, when, which part, which parameters, with files attached (cutting
-parameters, DAW session export). The room environment around them is
-logged by the sensors above.
+The Sibert stamper-prep machines and the shrink wrapper produce no machine
+data, and neither does the mastering chain on the Agnew route. They get
+station check-ins: who, when, which part, which parameters, with files
+attached (cutting parameters, DAW session export). The room environment
+around them is logged by the sensors above.
+
+If the lathe is a Sillitoe SDMS instead, its Space / Time Control software
+(a vendor application on the cutting room's own PC, which stays an
+appliance) writes files worth collecting: the master cue sheet (catalogue
+number, side, matrix number, engineer, groove diameters per track), an
+Open Groove export of the groove itself, the project file, and a
+stylus-hours counter. They are dropped on an SMB share on the cutting
+station and attached to the cutting session against the lacquer ID, the
+same watcher pattern as the metrology exports below. See
+[vendor landscape](suppliers/vendor-landscape.md).
 
 ## QC instrument integration