Better composter

**All 9 Composter States Covered (`level=0` to `level=8`):**
  - **Level 0 (Empty):** Recessed dark wooden gauge column with subtle graduated tick marks for each fill stage.
  - **Levels 1–7 (Filling):** Progressive organic green fill column paired with a high-contrast horizontal fill indicator line aligned with the internal compost height (`Y = 3, 5, 7, 9, 11, 13, 15`).
  - **Level 8 (Ready / Bone Meal):** Distinct bone-meal ivory/white indicator bar and full gauge highlight so harvest-ready composters stand out immediately across farms and redstone setups.
- **360° Exterior Visibility:** Renders on all four exterior faces (`north`, `south`, `east`, `west`) while preserving the default vanilla wood texture on the interior walls and 3D internal compost layers (`composter_contents1`–`7` and `composter_contents_ready`).
- **Vanilla-Native Pixel Art:** Built directly on the default 16×16 composter palette to blend seamlessly with vanilla blocks