Section folding with persistent memory

[rayeddev]

Vision

Collapse sections you don't care about. Fold state persists per file across sessions.

Behavior

• Click a heading or use zc/zo to collapse/expand
• Folded sections show heading + a "..." indicator with child count
• Fold state stored in VS Code extension globalState, keyed by file path
• Reopen a file tomorrow → same folds

Open Questions

• Fold at which heading levels? All? Only H2+?
• Should folding aggregate content stats (e.g., "3 subsections, 42 lines collapsed")?
• How to handle fold state when document structure changes (headings renamed/moved)?
• Visual treatment: subtle animation or instant toggle?

Why This Matters

Most requested power-user feature in any doc viewer. Turns a 500-line spec into something workable.