Fix Base Metals sconce compatibility and metal toughness

[SkyBlade1978]

What changed

• Offer each Base Metals sconce material only when the installed Base Metals jar includes its block texture. This avoids untextured Antimony, Bismuth, and Pewter variants in the older 2.4.0.11 build.
• Scale blast resistance and mining hardness by metal, and preserve the selected metal when a sconce is mined or picked. An Adamantine sconce no longer drops as iron.
• Use Base Metals' exact Cold-Iron and Star-Steel nugget names so their sconce recipes register. Other metal recipe names remain unchanged.
• Preserve all 16 upholstery colours when either padded bench form is mined. The colour tile entity stays available until Forge creates the drop; bench joining logic is unchanged.

Verification

• Full clean/check/build/Javadoc, catalog, resources, metadata, namespace, repository hygiene, artifact, checksum, and Eclipse gates passed locally.
• Packaged Forge server probes passed with Base Metals 2.4.0.11 and 2.5.0-beta4.238 plus their matching OreSpawn builds. All available sconce metals have one recipe (19 and 22 respectively); Adamantine placement, mining, pick-block, and single correct drop also passed.
• A packaged Forge 1.10.2 server probe reproduced the original red-drop bug before the fix, then verified spawned item metadata and Color NBT for all 16 colours on both padded bench forms. It also verified purple drops from the base and another part of wooden beds, canopy beds, wingback chairs, and thrones.
• Unit tests cover legacy and current texture layouts, metal hardness/resistance, and the exact Cold-Iron and Star-Steel Ore Dictionary names.