feat(api/runtime): java-style assets and localization sync

WeaveLoader.API/mod_assets/README.md

@@ -2,9 +2,9 @@
 
 Placeholder textures for the missing block and missing item (unresolved mod content).
 Stored in `mod_assets/` to avoid conflict with the `Assets/` C# source folder (Windows case-insensitivity).
-Copied to `assets/blocks/` and `assets/items/` in the build output.
+Copied to `assets/weaveloader.api/textures/block/` and `assets/weaveloader.api/textures/item/` in the build output.
 
-- **Blocks:** `mod_assets/blocks/missing_block.png` → icon `weaveloader.api:missing_block`
-- **Items:** `mod_assets/items/missing_item.png` → icon `weaveloader.api:missing_item`
+- **Blocks:** `mod_assets/weaveloader.api/textures/block/missing_block.png` → icon `weaveloader.api:block/missing_block`
+- **Items:** `mod_assets/weaveloader.api/textures/item/missing_item.png` → icon `weaveloader.api:item/missing_item`
 
 These are used when a world contains blocks or items from mods that are no longer installed.