Cosmetics framework: elytra skin slots

Description

Cosmetic customization (custom elytra textures/skins) is the primary monetization and progression hook. A framework for equipping, storing, and rendering custom elytra skins must be in place for release.

Acceptance Criteria

• CosmeticEntity DB schema: player UUID, cosmetic type (ELYTRA_SKIN), cosmetic ID, unlocked date
• A player's equipped elytra skin is loaded on join and applied to their armor slot
• At least 3 default skins are shipped with the server (resource pack textures)
• /cosmetics command opens a chat-menu or inventory UI showing owned and available skins
• Selecting a skin equips it immediately (visible to all players in the instance)
• Skin unlocks are gated by a CosmeticUnlockService (extensible for future monetization)
• Unit test: equip skin → verify armor slot has correct NBT / texture data

Technical Details

• Elytra texture customization uses resource pack + item NBT in Minestom
• CosmeticComponent on the player ECS entity holds the active cosmetic set
• Framework must be extensible (future: trails, aura effects)

Dependencies

• "Persist player profiles on first join" (Alpha) must be done first for the player entity

Estimate

L

First verify that “Persist player profiles on first join” is complete, then inspect the player ECS entity and existing profile persistence. Map the CosmeticEntity schema, CosmeticComponent, CosmeticUnlockService, and /cosmetics entry point before implementing the acceptance criteria. Done means skins persist, equip visibly, ship with three defaults, and the unit test verifies the armor-slot NBT or texture data.