[STORY] v4-S22: Implement navigation (sidebar, breadcrumbs, TOC)

[raifdmueller]

User Story

As a documentation reader, I want clear navigation with sidebar, breadcrumbs, and per-page table of contents.

Acceptance Criteria

Given a multi-section documentation site
When I navigate between pages
Then the sidebar highlights the current page and section
And breadcrumbs show the path from root
And a per-page TOC is generated from heading structure

Priority: Should

Epic: v4-E4 (#6)

Blocked by: v4-S20

[raifdmueller]

Analysis

Current Navigation (Docsy theme)

• Left sidebar: section menu (td-sidebar)
• Right column: page-level TOC (on XL screens)
• Top nav: main menu bar
• Breadcrumbs (hidden on mobile)

v4 Navigation Improvements

1. Sidebar: Collapsible sections, highlight current page, remember state
2. Breadcrumbs: Always visible (not just desktop)
3. TOC: Generated from heading structure, scrollspy highlighting, sticky on desktop
4. Mobile: Hamburger → slide-out sidebar

TOC Generation

AsciiDoctor CLI can generate TOC HTML. Alternatively, extract headings from rendered HTML via simple regex in the SSG.

🤖 Generated with Claude Code