refactor: Valve mirror module, golden menu test, local and CI checks

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.editorconfig

@@ -0,0 +1,15 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+[*.{yml,yaml,qml}]
+indent_size = 2
+
+[Makefile]
+indent_style = tab