feat: add missing project files and fix architecture compliance

- Add LICENSE file (MIT)
- Add CONTRIBUTING.md with generator-first workflow guidelines
- Add Makefile with comprehensive development commands
- Add .editorconfig for consistent code formatting
- Add CHANGELOG.md for version tracking
- Remove inconsistent non-variant files that bypassed generator architecture
- Fix installation script to use variant-specific paths (prevent config overwriting)

.editorconfig

@@ -0,0 +1,48 @@
+# EditorConfig for Everforest Resources
+# https://editorconfig.org/
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 2
+
+[*.{js,mjs,ts,json}]
+indent_size = 2
+
+[*.{yml,yaml}]
+indent_size = 2
+
+[*.{md,txt}]
+trim_trailing_whitespace = false
+max_line_length = 80
+
+[*.{sh,fish,zsh}]
+indent_size = 2
+
+[*.{toml,conf,ini}]
+indent_size = 2
+
+[*.{xml,html}]
+indent_size = 2
+
+[*.{css,scss}]
+indent_size = 2
+
+[*.{lua,py}]
+indent_size = 4
+
+[Makefile]
+indent_style = tab
+indent_size = 4
+
+[*.go]
+indent_style = tab
+indent_size = 4
+
+[COMMIT_EDITMSG]
+max_line_length = 72