Add specs and 1kg packages for ELEGOO ASA line

[crzykidd]

Fills out the ELEGOO ASA line — adds print specifications and 1kg packages to the
existing colors and adds the colors ELEGOO sells that were missing.

Materials

• Enriched (2): ASA Black, ASA White — added properties (were empty).
• New (4): ASA Blue, ASA Grey, ASA Red, ASA Green — color (Green left without a
  hex for now), photo, and properties.

Properties from the official ELEGOO ASA spec sheet (same for all):

• Nozzle 240–270 °C, bed 90–100 °C, chamber 45–60 °C (enclosure required)
• Drying 80 °C / 8 h, density 1.09 g/cm³, recommended nozzle ≥0.2 mm
• Spec-sheet values with no schema field (melt index, melting temp, Vicat, HDT,
  tensile/elongation/bending/impact, print speed, humidity) are omitted.

Packages (6, new)

• elegoo-asa-{color}-1kg, 1000 g, 1.75 mm, on elegoo-cardboard-spool-1kg
• brand_specific_id = ELEGOO SKU (SPUS-EL-3DF-AS07xx); variant product URL on the package
• GTIN-less for now (no barcodes on the listing) — backfillable later

Product: https://us.elegoo.com/products/asa-filament-1-75mm-colored-1kg
make validate passes; README/manifest untouched.