Rspack webpack gap tracker

Tracking targets

• Main tracking issue: https://github.com/web-infra-dev/rspack/issues/14556
• Completed feature comment ID: 4785525873
• Missing test comment ID: 4785526309
• Native CSS tracking issue: https://github.com/web-infra-dev/rspack/issues/14002

Required output shape

Keep the issue and comments as lists, not prose-only summaries.

• Main issue body: missing Rspack features compared with webpack, grouped by implementation recommendation.
• Completed feature comment: webpack compatibility features that Rspack has completed.
• Missing test comment: webpack tests missing from Rspack that are not already covered by a missing feature or PR-specific feature gap.

Every update to the issue body or either placeholder comment must include a visible update time, using the local timezone when possible: