Normalize wiki markdown filenames and fix markdown rendering/link issues

[nevalsar]

Summary

This PR improves wiki content consistency and markdown reliability by normalizing filenames/slugs and fixing markdown/math formatting issues.

What Changed

• Renamed wiki markdown files to lowercase kebab-case for consistency.
• Updated internal wiki/navigation references to match renamed slugs.
• Corrected markdown formatting issues in planning content (especially Frenet/math-heavy sections).
• Improved equation/text rendering compatibility in markdown pages.
• Fixed malformed markdown link patterns in affected pages.