[Bug]: Mermaid diagrams don't render in the mobile app #24212

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/mobile

Steps to reproduce

1. Open a thread in the mobile app where the agent replied with a fenced ```mermaid code block (or a proposed plan containing one).
2. View the message.

Expected behavior

The diagram renders, as it does in the web and desktop chat since #21472 (Mermaid via pele).

Actual behavior

The mobile app shows the raw Mermaid source as a plain code block. Mobile renders markdown through react-native-enriched-markdown (apps/mobile/src/native/EnrichedMarkdownText.tsx), which has no Mermaid handling, and apps/mobile has no Mermaid or pele dependency.

Impact

Minor bug or occasional failure

Version or commit

main @ 5bb54a0

Environment

T3 Code mobile app (iOS and Android; the code path is shared). Web and desktop are unaffected.

Logs or stack traces

No response

Screenshots, recordings, or supporting files

No response

Workaround

Copy the Mermaid source into a viewer, or open the thread on web or desktop.