The Abyss v16 - Fauna Balance Pass

Single mod id/namespace: abyss
Portal: exact 2x2 interior, Gilded Mithril Block frame, Abyss Key ignition.

Fauna balance changes from v15:
- Aquamirae and Naturalist anglerfish now have distinct depth roles.
- Aquamirae Anglerfish moved upward: rare in Sunlit Expanse and Twilight only.
- Naturalist Anglerfish is removed from Sunlit Expanse and Twilight, leaving its normal ocean-tag spawn integration to populate Midnight and Abyssal Floor only.
- Aquamirae fauna is less common overall in The Abyss:
  * Spinefish reduced in Sunlit/Twilight.
  * Abyssal Scyphoid reduced in Midnight/Abyssal Floor.
  * Maw spawn weight reduced on Abyssal Floor.
  * Aquamirae Anglerfish weight reduced to 1 in its two remaining depth bands.
- Supplied Aquamirae config is expected to use softened Maw and Anglerfish combat attributes.

Aquamirae combat tuning in supplied config:
- Maw: health 14-18, attack 3, lower knockback/follow range and slightly lower movement range.
- Anglerfish: health 22-30, armor 1-2, attack 4, knockback 0.6, follow range 40, movement 0.32.
- Aquamirae biome_spawner_mode remains NONE so The Abyss keeps explicit control of its Aquamirae spawn lists.

Dependencies added/carried:
- Aquamirae 7.2.3+
- Naturalist 2.0.3+
- FTB Ocean Mobs 21.1.4+
- GeckoLib 4.9.2+

Credits:
The Abyss was inspired by and originally grew out of Ocean World Dimension by Altias (MIT). Ocean World supplied the original endless-ocean foundation that led to The Abyss. The Abyss Key is the remaining direct carry-over.

Test status:
- Structural/package validation completed.
- Fauna changes are not yet verified in-game; confirm Naturalist Anglerfish appears only in Midnight/Abyssal Floor and Aquamirae Anglerfish only in Sunlit/Twilight.
