Code Cleanup: Remove debug calls and dead code

Problem/Motivation

The codebase contains commented-out code blocks and development debug calls (dump(), dsm(), etc.). These artifacts should not be present in a production-ready module intended for Drupal.org.

Proposed resolution

• Remove all dump(), dsm(), dpm(), kint() and other debugging calls.
• Delete all blocks of commented-out code.
• Rename local variables and properties to follow Drupal's camelCase standard (e.g., $myrest_route_metatag_id to $myrestRouteMetatagId).

Remaining tasks

Perform a global cleanup and verify coding standards.

User interface changes

None.

API changes

Internal variable renaming only.

Data model changes

None.