Allow line break/list formatting in Call Summary field (parity with message formatting)

Description:

Currently, the Call Summary field renders the raw string as-is, so <br> tags (and presumably other formatting) don't get parsed into line breaks like they do in regular messages.

This makes call summaries with multiple sections (call reason, key points, outcome, follow-up) hard to scan — everything runs together as one block of text instead of showing the same structured breaks we can apply elsewhere.

Ask: Support line break and list formatting in the Call Summary field, consistent with how <br> is already handled in standard messages.

Use case: We generate structured call summaries (reason → key points → outcome → follow-up) via the API. Readable line breaks make these scannable for agents reviewing call history, instead of one dense paragraph.