Crumbling Ore

Ore does not vanish on the first hit.

An ore block stays in the world, drops its loot, and visibly fractures, giving out only
after several harvests. A vein becomes somewhere worth standing rather than a thing you
clear in a second, and a drill parked on a patch has something to work.

Works with anything

The mod adds no blocks and no items. It keys off the c:ores tag and each block's own
loot table, so modded ores are included automatically, and ore fields placed by worldgen
mods become far more interesting to work. Machines from other mods get the same behaviour,
because it hooks the break rather than the block.

Config

crumbling.enabled = true       # turn the whole mechanic off  
crumbling.harvestsPerOre = 8   # harvests to exhaust one ore; 1 is vanilla behaviour  

Each harvest drops the block's normal loot, so raising harvestsPerOre raises both the
total yield of every ore in the world and the time to extract it.

How it holds together

Progress cannot live on the blocks, because a property cannot be added to another mod's
block. It lives in per-dimension saved data keyed by position, and only partially worked
ore is tracked — untouched blocks have no entry and exhausted ones are dropped, so the map
scales with mining in flight rather than with how much ore exists.

The visible wear reuses vanilla's block-breaking crack overlay, which already renders over
arbitrary blocks and syncs to clients, so no models or textures are needed and modded ores
get the look for free.

Silk Touch takes a pristine node whole, in one hit, and that is not duplication: one
block in, one block out. A node that has already been worked cannot be lifted intact,
because the harvests taken out of it cannot be put back; the enchantment is ignored and the
node crumbles as usual, with a sound and a message rather than a silent refusal.

Pistons cannot move a fractured node, since its damage is bound to a position and moving
the block would leave the damage behind and present a pristine ore elsewhere. Explosions
and block replacement drop the tracking instead of leaving it for the next ore to inherit.