[CLEANUP] Empty calculator module should be removed or implemented

[Prestgg1]

Issue\ncrates/transpiler/src/calculator.rs is an empty file (0 lines) but is included in the module.\n\n## Current Code\n// crates/transpiler/src/calculator.rs\n// (empty file)\n\n## Impact\n- Dead code in the codebase\n- Confusing for contributors\n- Increases build time slightly\n\n## Recommendation\nEither:\n1. Remove the file and module reference\n2. Implement a proper expression calculator for optimization\n\n## Files\n- crates/transpiler/src/calculator.rs\n- crates/transpiler/src/lib.rs (module declaration)\n\nLabels: cleanup, good first issue