feat: refactor plugin architecture, enhance linting, CI & tooling

- Major refactor of core Fish functions for modularity, caching, and error handling
- Improved `.editorconfig` and Makefile for stricter formatting and linting standards
- Expanded linting support: added EditorConfig checks, auto-install for missing tools, and Makefile targets
- Enhanced CI workflow with clearer permissions and job steps in GitHub Actions
- Updated documentation in `README.md` and `CLAUDE.md` to reflect new features, advanced developer tools, and contribution guidelines
- Improved Node.js version manager detection, switching, and installation logic
- Added/updated utility functions for configuration, silent mode, notifications, and version extraction
- Various bug fixes, code quality improvements, and expanded test coverage

.editorconfig

@@ -9,3 +9,20 @@ trim_trailing_whitespace = true
 [*.fish]
 indent_size = 4
 indent_style = space
+
+[Makefile]
+indent_style = tab
+max_line_length = 80
+
+[*.sh]
+max_line_length = 120
+indent_size = 2
+indent_style = space
+
+[*.yml]
+indent_size = 2
+indent_style = space
+
+[*.json]
+indent_size = 2
+indent_style = space