Update copilot instructions and wiki-fargo3d submodule

.github/copilot-instructions.md

@@ -6,3 +6,27 @@ Always use a plain lowercase 'x' for dimensions and multiplication.
 
 - WRONG: `25mm × 25mm × 25mm`
 - CORRECT: `25mm x 25mm x 25mm`
+
+# Wiki Tagging Rules
+
+All challenge pages in the wiki must include YAML front matter with a `tags` list.
+
+## Tagging Standards
+
+1. **Challenge Tag**: All challenge pages must have the `challenge` tag.
+2. **Number Tag**: All challenge pages must have a sequential number tag in the format `challenge-XXX`.
+   - `challenge-001`: October 2025
+   - `challenge-002`: November 2025
+   - `challenge-003`: December 2025
+   - Increment for subsequent months.
+3. **Archive Tag**: Past challenges must have the `archive` tag.
+
+## Example Front Matter
+
+```yaml
+---
+tags:
+ - challenge
+ - challenge-002
+---
+```