Prevent markdown rendering in post title and topic fields

Summary

When creating a post, the title and topic fields currently accept and render markdown (e.g., bold via asterisks). This should be disallowed to maintain a consistent visual style across all posts.

Steps to Reproduce

1. Create a new post.
2. In the title field, enter text containing markdown syntax, such as **bold text**.
3. In the topic field, enter similar markdown syntax.
4. Submit the post.
5. View the post; observe that the markdown is rendered (e.g., bold text appears bold).

Expected Behaviour

Markdown syntax in the title and topic fields should not be rendered. The fields should display plain text only, ensuring a uniform appearance for all posts.

Actual Behaviour

Markdown syntax in the title and topic fields is rendered (e.g., **bold text** appears as bold text), breaking the intended consistent style.

Environment

Not provided.

Reported by Lensflare via DevPlace.