Improves handling of explicit interface implementations in the source generator, ensuring that methods explicitly implemented from base interfaces are not redundantly emitted and that diagnostics are not incorrectly reported. Updates method model and emitter logic to track explicitness, normalizes method lookup keys, and adds polyfills for Index/Range for legacy targets. Updates tests and snapshots to reflect correct code generation.

Corrects 'installWorkflows' to 'installWorkloads' in both ci-build and release workflows. Also adds the CODECOV_TOKEN secret to the ci-build workflow for code coverage reporting.

The installWorkloads parameter was removed from both ci-build.yml and release.yml GitHub Actions workflows, simplifying the configuration.