Rename section index files to match their titles (tutorials.md,
reference.md, how-to.md, explanation.md) so all filenames are unique.
Convert all path-based wiki-links to simple filename format for better
obsidian.nvim compatibility.
Update doc-filenames task to no longer skip index.md files.
Update doc-links task to reject path-based links containing '/'.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
