Standardize screen position naming to snake_case

- Update screen position naming from camelCase to snake_case (top_left, top_right, bottom_left, bottom_right)
- Refactor getActive route to use SCREEN_POSITIONS constant for DRY code
- Update documentation to reflect new file naming convention
- Remove unnecessary console.log for internal network requests in middleware
- Improve code maintainability and consistency across the codebase

🤖 Generated with [Claude Code](https://claude.ai/code)

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

lib/constants.ts

@@ -45,10 +45,10 @@ export const SCREEN_POSITIONS = [
     'large',
     'left', 
     'right',
-    'topLeft',
-    'topRight',
-    'bottomLeft',
-    'bottomRight'
+    'top_left',
+    'top_right',
+    'bottom_left',
+    'bottom_right'
 ] as const;
 
 export const SOURCE_SWITCHER_NAMES = [