Detail matrix richness: notes markers + resources/known-issues section

[elkraneo]

Context

Current detail view has good baseline support data but limited contextual signals.

Idea

Increase matrix/detail richness with:

• Version/note markers (e.g. new in 26, caveats).
• Optional Known issues and Resources section/tabs under matrix.

Scope

• Data model extension for per-feature annotations.
• UI rendering for markers and linked resources.

Acceptance Criteria

• Feature detail can display marker chips tied to support data.
• Known issues/resources area renders when data exists.
• Empty state remains clean when no extra data is present.