Closes #5 fix: show re-run enrichment button for all block types, not just thesis

[justutsav]

Closes #5
Summary:

• The "Re-run AI enrichment" button in the tile card header was previously only rendered for blocks with contentType === "thesis", leaving all other block types without a way to trigger re-enrichment.
• The button is now shown for all block types.
  • For thesis blocks, it still passes "thesis" as the enrichment type; for other blocks it passes undefined.
  • For Non-thesis blocks, i't shows the button at reduced opacity (dimmed) with full opacity on hover to subtly distinguish behavior.
• Also Button tooltip has been updated from "Refresh thesis synthesis" to "Re-run AI enrichment" to reflect the broader scope.