Compound storage for tens of colours; stamper prep open to galvanics

User, October 2026: special designs will need tens of colours, so the
compound store needs far more space, with maybe a few silos for black and
the standard colours; and the wall between stamper prep and galvanics is
to go.

- pressing-line: "Compound storage" bullet (colour store with pallet
  racking, ~100 positions in the Payap model, estimate; outdoor silos
  proposed; compound stays on the ground floor, ~160 to 270 t a year at
  the mature fleet; sacks vs big bags decides the silo filling).
- galvanics: stamper prep open to galvanics, one clean zone.

docs/equipment/galvanics.md

@@ -94,6 +94,10 @@ What this changes in the plan:
   chemical day store at the duct head. The
   [Payap scenario model](../site-candidates.md#payap-scenario-model-october-2026) draws it as a 12 × 10 m building
   (estimate).
+- **Stamper prep open to galvanics (October 2026).** No wall between the
+  galvanics room and stamper prep: stampers go from the last bath straight
+  to the Sibert line inside one clean zone, as the
+  [Payap scenario model](../site-candidates.md#payap-scenario-model-october-2026) draws it.
 - **Space.** One of each unit is ~5.6 m² of footprint (PASU 1.56, PMPB
   1.23, PPPU 1.32, PDPU 1.44 m²), plus 500 mm service access behind the two
   tank units and working space around them: comfortably inside the 80 to