bug(operator-queue): markdown in approval/question asks renders as raw text on some surfaces (portal asks, options, resolved history) #3115

Summary

Markdown written by agents in approval and question requests (ask_operator asks, approvals, decisions) is not rendered consistently. On some surfaces the reader sees raw syntax like **bold**, `code`, - list markers and [text](url). On others it renders. The same ask looks different depending on where the operator or user answers it.

Context

Reported by the operator with a screenshot of an approval/question chain showing unrendered markdown. Agents naturally write their questions in markdown, so any surface that shows the text verbatim becomes hard to read, especially for multi-line asks with lists or code.

Current state on dev:

• Operator queue (src/frontend/src/components/operator/QueueCard.vue, QueueItemDetail.vue): the question renders as markdown, but the title, the answer options, and the context/details values show as plain text.
• Portal asks (src/frontend/src/components/portal/PortalAsks.vue): the question shows as raw text (whitespace-pre-wrap), so markdown syntax is visible.
• Resolved items (src/frontend/src/components/operator/ResolvedCard.vue): show the title/answer as plain text.

Acceptance Criteria

• An ask's question renders as markdown on every surface where it can be answered or reviewed: operator queue card, queue item detail, portal asks, and resolved history
• Markdown in inline fields (title, answer options, the given answer) renders inline formatting only (bold, italic, code, links), with no block elements that would break the layout
• Rendering goes through the existing sanitized markdown path. Agent-authored text never reaches v-html without sanitization, and it follows the same class allowlist as other agent-authored markdown (see bug(security): Tailwind utility classes in agent-authored chat/report markdown reach the page unfiltered — extend the ent#537 class allowlist beyond the canvas #2567)
• A multi-line ask with a list, inline code and a link looks the same in the operator queue and in the portal
• Plain-text asks (no markdown) look the same as they do today

Technical Notes

Related: #2771 (markdown in canvas table cells), #2567 (class allowlist for agent-authored markdown).