pc: fix copper tool speeds in materials.json (1.21.9-26.1)

[Pix3lPirat3]

Copper tools were generated at speed 1.0 because the generator's speed table had no copper entry; vanilla is 5.0. Regenerated with PrismarineJS/minecraft-data-generator#87; 1.21.10 shares pc/1.21.9.

Since 1.21.9 every copper tool is listed at speed 1.0 in materials.json - the generator's name-prefix speed table had no copper entry (fixed in PrismarineJS/minecraft-data-generator#87; vanilla ToolMaterial.COPPER is 5.0). prismarine-block digTime() therefore reports copper tools ~5x too slow: copper pickaxe on stone 2300 ms instead of 450, copper shovel on dirt 750 ms instead of 150.

Regenerated materials.json for 1.21.9 (also 1.21.10), 1.21.11 and 26.1: exactly 16 entries change per file, all copper tools 1.0 -> 5.0, nothing else. digTime() for every diggable block x copper pickaxe/axe/shovel/hoe matches the vanilla formula on all three versions (3887/3888, the remaining case being bamboo's pre-existing missing axe composite, identical for every tier) when combined with #1307. Live on vanilla 26.1 with mineflayer 4.39.0: copper pickaxe on stone 453 ms (was 2307), copper axe on oak log 600 ms (was 3010).

[rom1504]

Astra agent review — AI-generated, not manually written by the maintainer.

These copper corrections are already incorporated in master through minecraft-data#1310, whose merge commit 08a8e3a includes this copper commit plus the shears correction. This open PR therefore appears superseded; it does not need another data merge. Generator#87 (also included in generator#88) remains the producer-side work to preserve the values on regeneration.

I verified all 48 changed entries and compared the 1.21.9/26.1 tables with generator#87's exact-head CI artifacts. Real prismarine-block checks produce the expected copper digging times. Focused schema checks pass (97); the full local run hit timing guards, so I do not claim a clean full-suite run.

Skills used: prismarine-protocol-data-review separated landed data from the still-pending generator; prismarine-architecture-review checked the shared producer/consumer contract; prismarine-review followed actual commit ancestry instead of treating open status as unmerged content.

[Pix3lPirat3]

Superseded by #1310 (merged, commit 08a8e3a includes this copper correction plus the shears fix). Generator#87/#88 remain the producer-side work to preserve the values on regeneration.