chore: remove MCreator workspace file, backups and obsolete docs

- Delete custom_ore_gen.mcreator (MCreator workspace definition) and
  the tracked .mcreator/ backup directory; add .mcreator/ to .gitignore
- Delete CONFIG_INTEGRATION_GUIDE.md (obsolete MCreator how-to,
  self-described as historical)
- README/CLAUDE/AGENTS: update package path (com.aulyrius.customoregen),
  drop MCreator workflow instructions, fix stale config/item docs

AGENTS.md

@@ -122,7 +122,7 @@ The project was originally generated by MCreator but is no longer maintained wit
 ## 6. Common Tasks
 
 - **Adding a New Ore:**
-  1. Create Block & Item (MCreator/Manual).
+  1. Create Block & Item classes manually (copy an existing ore as template).
   2. Add JSONs: Loot Table, Configured Feature, Placed Feature, Biome Modifier.
   3. Register in `CustomOreGenModBlocks` and `CustomOreGenModItems`.
   4. Update `OresCommand.java` lists (e.g., `COLD_ORES`, `HOT_ORES`) to make it discoverable.
@@ -130,13 +130,13 @@ The project was originally generated by MCreator but is no longer maintained wit
   6. Add to `ModConfigs.java` for generation parameters (vein size, count, etc.).
 
 - **Modifying Logic:**
-  - Check `procedures/` for game logic (often MCreator generated).
+  - Check `procedures/` for game logic.
   - Check `event/` for event-driven logic.
   - Always verify if logic changes need a corresponding test update.
 
 ## 7. Safety & Verification
 
-- **Backups:** If you are unsure about MCreator regeneration, backup the file before editing.
+- **Backups:** All files are hand-maintained; standard git workflow is sufficient.
 - **Verification:**
   - Always run `./gradlew build` after changes to ensure no compilation errors.
   - If you touch config files, ensure `ModConfigsTest` still passes.
@@ -146,7 +146,7 @@ The project was originally generated by MCreator but is no longer maintained wit
 ```
 src/
 ├── main/
-│   ├── java/net/mcreator/customoregen/
+│   ├── java/com/aulyrius/customoregen/
 │   │   ├── block/       # Block definitions
 │   │   ├── config/      # Configuration classes
 │   │   ├── event/       # Event handlers
@@ -155,5 +155,5 @@ src/
 │   │   └── procedures/  # Game logic procedures
 │   └── resources/       # Assets and data (textures, models, lang)
 └── test/
-    └── java/net/mcreator/customoregen/  # Unit tests
+    └── java/com/aulyrius/customoregen/  # Unit tests
 ```