[Bug]: Mermaid diagrams don't render in the mobile app#24223

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. react-native-enriched-markdown has no Mermaid handling and apps/mobile has no pele dependency.

Impact

Minor bug or occasional failure

Version or commit

main @ 5bb54a0f77

Environment

No response

Logs or stack traces

Screenshots, recordings, or supporting files

Workaround

No response