v0.12.0 — Ocean Overhaul, properly named

BREAKING: full identity rename oceanstarter → oceanoverhaul — mod id, every registry id, lang keys, packages. Worlds created with v0.11.0 or earlier will lose placed mod blocks/items when upgrading. Done now, before anyone's worlds depend on it.

Also in this release:

• Helmet sprite touch-up (and regenerated docs/icons to match)
• Housecleaning: texture painters consolidated under scripts/, docs corrected to verified reality (36 blocks / 68 items / 74 recipes / 12 gametest suites), dead code swept, recipe table caught up
• All tooling is now checkout-location independent (scripts derive the repo root themselves)

Gates: build green, 52/52 gametests, 322 data files validated.