Use `MarkdownTextFlow` for Summarization Content

Context and Problem Statement

This decision record concerns the UI component that is used for rendering the content of AI summaries.

This ADR previously chose a WebView for this purpose. At that time, a WebView was the only considered option that could both render Markdown and let the user select and copy text. Chat messages, in contrast, are rendered with a Markdown parser whose AST is turned into JavaFX TextFlow nodes (ADR-0036).

Since then, SelectableTextFlow gained text selection and copying, and the AST-to-TextFlow renderer used for chat messages was extracted into the reusable MarkdownTextFlow component. The premise that summaries need a different, heavier rendering path than chat messages therefore no longer holds.

Which component should render the summary content?

Decision Drivers

Same as in ADR-0036:

Looks good (renders Markdown)
User can select and copy text
Has good performance

In addition:

Consistency with how chat messages are rendered

Considered Options

Same as in ADR-0036.

Decision Outcome

Chosen option: “Use MarkdownTextFlow”, because it renders summaries through the same Markdown-to-TextFlow component already used for chat messages, giving both surfaces a single code path.

SelectableTextFlow now supports selecting and copying text, which was the sole reason this ADR originally preferred a WebView over the chat rendering approach. With that gap closed, reusing MarkdownTextFlow gives identical formatting and selection behavior across summaries and chat messages and removes the summary-specific HTML rendering path.

The performance argument that ADR-0036 raised against WebView never applied to summaries: there is only one summary content pane in the UI, and switching entries rebinds that single pane instead of adding components. A single MarkdownTextFlow is therefore unproblematic here as well.

Consequences

Good, because summary and chat content render and behave consistently, using one component.
Good, because no separate Markdown-to-HTML rendering path has to be maintained for summaries.
Neutral, because the summary pane is a single instance, so the per-message performance concerns from ADR-0036 do not arise.

Pros and Cons of the Options