2025 10 21 Add Rejectaisuggestions

<!-- entry: {"id":"2025-10-21-26-10-suggestion-instead-styling-7fb36069","kind":"behavior","migrationNotes":["Use `SuggestionLineBreak` instead of `BlockSuggestion` for suggestion styling."]} -->

• suggestion-kit, suggestion-node, block-discussion: Use SuggestionLineBreak instead of BlockSuggestion for suggestion styling.

<!-- entry: {"id":"2025-10-21-26-10-ai-api-keep-comments-visible-after-61174ea8","kind":"behavior","migrationNotes":[]} -->

• ai-api: Keep AI comments visible after the stream finishes.