Epic 16 — Multi-dimension: Nether & End support

[JROtto5]

Extend the engine to the Nether and End with dimension-aware behavior.

• Nether mode: ancient-debris hunting at the right Y, blast-resistant awareness
• NO water bucket in Nether — different lava-safety strategy
• Ghast/piglin/hoglin awareness and avoidance
• Bastion / fortress detection as high-value stash targets
• End mode basics: obsidian pillars, void avoidance, chorus terrain
• Dimension-aware Y targets and ore tables
• Nether-roof travel option (if the server allows it)
• Portal detection and safe handling
• Per-dimension config profiles
• Xaero waypoints tagged by dimension

[JROtto5]

Shipped v5.22: ✅ dimension-aware mining depth — Nether holds the ancient-debris band (Y14, above the bedrock floor), End mines flat at the start level, Overworld dives to Y-59. Ancient debris already in the ore-seek list.