Add raw PVC per-lot and packaging QC gates to quality automation spec

docs/quality-automation.md

@@ -109,6 +109,64 @@ What only this layer can catch: wrong master cut into good-looking grooves,
 EQ/mastering errors, and speed/pitch problems. Optical and audio layers are
 complements, not substitutes.
 
+## Raw PVC compound QC, per lot
+
+Every incoming compound lot passes a gate before release to production, and
+the lot ID follows every record pressed from it:
+
+- **Paper first**: supplier certificate of analysis per lot, checked against
+  the agreed specification; a retained sample of every lot is archived
+- **Moisture**: verify the compound is within the moisture spec before it
+  reaches the extruder (moisture causes surface defects and noise); a
+  benchtop moisture analyzer is a cheap, automatable check
+- **Melt behavior and thermal stability**: a melt-flow or rheology check per
+  lot catches drift in processing behavior, and a heat-stability check
+  matters specifically for PVC (degradation releases hydrochloric acid and
+  shows as discoloration and noise); these are standard plastics-lab
+  instruments with data export
+- **Color and appearance**: spectrophotometer reading against the reference
+  for black and colored compounds; granulate size and dust content by
+  sampling
+- **Release by test pressing**: a new lot, and especially a new supplier, is
+  released only after test pressings from that lot pass optical and audio
+  QC; this is the backbone of the local-supplier qualification protocol,
+  since qualifying Thai/regional compound against European references is an
+  explicit goal
+- **Regrind stream QC**: the in-house 20% recycled stream is its own
+  material source and needs its own gate: no labels, paper, or foreign
+  material entering the grinder, contamination checks on regrind batches,
+  and verification of the virgin/regrind ratio at the extruder; regrind
+  batch IDs are logged like any other lot
+
+## Packaging QC
+
+Packaging comes from local carton partners, so QC splits into an incoming
+gate and an assembly gate:
+
+- **Incoming cartons and sleeves, per delivery**: dimensional checks
+  (records must fit without force; spine width per title), board grammage
+  and thickness, print quality against the customer-approved proof
+  (spectrophotometer Delta E for color-critical jobs), lamination/finish,
+  and seam strength; results logged per packaging lot and fed back to the
+  partner
+- **Inner sleeves**: verified for scuff risk (surface finish matters more
+  than looks; a bad inner sleeve scratches every record put in it)
+- **Print inspection is automatable**: camera-based print inspection is a
+  mature field, and the same vision investment as the record label check
+  can cover jacket print defects
+- **Assembly verification, automated**: the highest-value check is that the
+  right record goes into the right jacket; scanning the runout matrix code
+  against the jacket barcode at the packing station makes mismatches
+  impossible rather than unlikely, and confirms inserts and extras per the
+  order's bill of materials
+- **Barcode verification** on every finished unit (a misprinted barcode is
+  a rejected delivery at the distributor)
+- **Shrink wrap and final visual** on a sampling basis
+
+Both gates write to the same traceability chain: compound lot and regrind
+batch attach to every press cycle, packaging lot and assembly checks attach
+to every order.
+
 ## The traceability payoff
 
 The natural record identity is **stamper ID + press ID + cycle timestamp +