Update CONTRIBUTING.md source URLs

- Replace Gist URLs with https://denpaio.github.io/CONTRIBUTING.md
- Update all references from Gist to generic "source"

Author: claude

CONTRIBUTING.md

@@ -1,14 +1,14 @@
 # Contributing Guidelines
 
-> **⚠️ Source of Truth**: [CONTRIBUTING.md on Gist](https://gist.githubusercontent.com/shikendon/2f6c3d48bba357bd094ca87ca5817802/raw/CONTRIBUTING.md)  
+> **⚠️ Source of Truth**: [CONTRIBUTING.md](https://denpaio.github.io/CONTRIBUTING.md)  
 > 
 > **MANDATORY: Version Check Before Any Work**:
-> - **ALWAYS verify this file matches the Gist source before making any changes**
+> - **ALWAYS verify this file matches the source before making any changes**
 > - If outdated, MUST update to latest version first via PR
-> - To check: `curl -s https://gist.githubusercontent.com/shikendon/2f6c3d48bba357bd094ca87ca5817802/raw/CONTRIBUTING.md | diff CONTRIBUTING.md -`
-> - To sync: `curl -o CONTRIBUTING.md https://gist.githubusercontent.com/shikendon/2f6c3d48bba357bd094ca87ca5817802/raw/CONTRIBUTING.md`
-> - DO NOT modify this file directly - all changes must be made in the Gist
-> - After Gist updates, submit a PR to update this repository's copy
+> - To check: `curl -s https://denpaio.github.io/CONTRIBUTING.md | diff CONTRIBUTING.md -`
+> - To sync: `curl -o CONTRIBUTING.md https://denpaio.github.io/CONTRIBUTING.md`
+> - DO NOT modify this file directly - all changes must be made in the source
+> - After source updates, submit a PR to update this repository's copy
 
 ## Code Standards
 
@@ -65,4 +65,4 @@ yamllint .
 
 ---
 
-<!-- For Claude Code: CRITICAL - Before any work, verify CONTRIBUTING.md is up-to-date with Gist source. If outdated, stop and request update via PR first. Strictly follow all standards above. Verify linter compliance before marking tasks complete. -->
+<!-- For Claude Code: CRITICAL - Before any work, verify CONTRIBUTING.md is up-to-date with source. If outdated, stop and request update via PR first. Strictly follow all standards above. Verify linter compliance before marking tasks complete. -->