[codex] Restore live disable draft preview

[rsdadada]

Summary

• Restore live preview updates while editing an existing hidden disable setting by overlaying the current same-name draft when generating a BindTarget.
• Keep new or renamed disable drafts explicit: drafts without an existing name match are not added until the right-side + action or DISABLE-page save synchronizes them.
• Include the current same-name draft in generated targets used by rendering, save, and export.
• Reload the generated target after saving from CONFIGS or PREVIEW so the editor's disable-config list stays synchronized; DISABLE-page saves keep the active draft intact.

Root cause

PR #213 removed the same-name draft replacement from genBindTarget(). That simplified save generation, but also removed the per-frame draft overlay that made edits to an existing hidden disable setting immediately visible.

This PR restores that replacement on a copied disable-config list. The staged source list is not mutated during rendering, and unmatched drafts are not implicitly added.

Validation

• Temporary JUnit regression tests passed before being removed as requested: same-name replacement, source-list isolation, and unmatched drafts not being added.
• .\gradlew.bat :common:test
• .\gradlew.bat build
• git diff --check
• GitHub Actions build