Add Pheenix galvanics flyers and Sibert stamper prep specs

docs/equipment/pheenix-alpha/: the four Pheenix Alpha electroforming flyers
(2024: PASU silvering, PPPU pre-plating, PDPU dual-cell plating, PMPB
passivation bench), renamed from their download hashes.
docs/equipment/sibert/: the VSP, VSF and VSC technical specifications
(2021), plus Sibert's 2008-09 optical-disc SPS literature and the 2008
Blu-ray stamper characteristics paper in sps-optical-disc-2009/. Two
byte-identical duplicates in the download were dropped.

New docs/equipment/galvanics.md, the metal-path counterpart to
pressing-line.md: datasheet tables for both ranges and what they change.
Pheenix is a second turnkey galvanics vendor next to Digital Matrix and
can quote lacquer-to-record as one vendor; neither range includes water
treatment. Utilities from the sheets (~27 kVA connected per line, DI water,
12-20 C cooling water, extraction sizes), ~5.6 m2 of footprint, and a cell
count estimate (one PDPU at the low end, two at the high end). The Sibert
machines are single-phase, 200/250/600 kg on castors, centre manually and
list no data interface; the VSC locates on the punched hole; the finisher's
water carries nickel. Weights, cycle times, prices and mould fit are listed
as quote questions.

Backlinks and small updates: README (bullet, layout tree, vendor list),
roadmap items 6 and 23, vendor landscape, supplier map, exhibitor briefing
(on-file notes, Sibert three-phase question answered), digital factory
(Pheenix PLC data, Sibert data question, RFQ clause 5), quality automation
(hardness on the centre slug, BD paper as the acceptance-spec model),
sustainability (finisher water), total investment block label (numbers
unchanged), scale (galvanics feeder note), crane weight table, process
flow, pressing-line stamper-fit question, plant page detail lines.

docs/quality-automation.md

@@ -97,6 +97,24 @@ industry practice, which is exactly the point: it makes every father, mother,
 and stamper a data-backed accept/reject decision before the next plating
 generation or press mounting.
 
+### Hardness on the centre slug
+
+From optical-disc practice, per the 2008 Blu-ray stamper working-group
+paper in
+[`equipment/sibert/sps-optical-disc-2009/`](equipment/sibert/sps-optical-disc-2009/):
+stamper hardness (micro-Vickers, HV0.3) is measured on the disc punched out
+of the centre, never on the part, and a freshly made-up nickel bath plates
+soft at first (from ~150 HV0.3 upward against a ~200 HV0.3 target for
+Blu-ray), which changes how stampers punch and finish. The vinyl centre
+punch (Sibert VSP) leaves one slug per stamper; marked with the part
+serial, it is a free per-stamper coupon for hardness and thickness, logged
+against the bath ID. The paper's limits are for Blu-ray and do not
+transfer, but its structure (thickness, flatness, hardness, back
+roughness, centre hole, eccentricity, burr, visual defects, each with a
+method) is the model for the stamper acceptance spec this plant still has
+to write. Equipment context in
+[galvanics and stamper prep](equipment/galvanics.md).
+
 ## Pressed record QC: three layers
 
 Full automated audio checking of every record is physically impossible: a