Replace heading # anchor markers with clean heading links

[x3ek]

Description

The toc extension in Python-Markdown generates <a class="headerlink">#</a> inside each heading. The # symbol is visually ugly and doesn't match a clean minimal theme aesthetic.

Desired behavior

Headings in posts and pages should link to their own anchor, but without showing a visible # marker. Options to evaluate:

• Configure the toc extension to use a different marker (e.g. empty string or a symbol)
• Use a custom toc extension that wraps the heading text itself in the anchor link
• Remove the headerlink entirely and use a different anchor strategy

Notes

• This is an engine change, not a theme change
• The # can currently be hidden via CSS in themes but that's a hack — the fix belongs in the engine
• Affects all themes