## Epic Phase 8 Complete: Documentation Infrastructure & Home Page

Added mkdocstrings[python] and mkdocs-autorefs to the docs dependency group, configured
plugins in mkdocs.yml, built the full DITA nav structure (Getting Started, Concepts,
How-To Guides, Reference, Architecture Decisions), created 4 section index pages with
Material grid cards, 24 stub pages for all nav entries, and updated the home page with
accurate status text and links to all sections.

**Files created/changed:**

- mkdocs.yml (plugins + nav restructured)
- packages/pyproject.toml (docs dependency group updated)
- docs/index.md (home page rewritten)
- docs/getting-started/index.md (new section index)
- docs/concepts/index.md (new section index)
- docs/guides/index.md (new section index)
- docs/reference/index.md (new section index)
- 24 stub pages across getting-started/, concepts/, guides/, reference/

**Functions created/changed:**

- N/A (documentation-only phase)

**Tests created/changed:**

- N/A (documentation-only phase)

**Review Status:** APPROVED with P2 fix applied (duplicate dependency consolidation)

**Git Commit Message:**

```
docs: add documentation infrastructure and DITA nav structure

- Add mkdocstrings[python] and mkdocs-autorefs to docs dependency group
- Configure mkdocstrings plugin with python handler (packages/src path)
- Build full DITA nav: Getting Started, Concepts, How-To Guides, Reference
- Create 4 section index pages with Material grid cards
- Create 24 stub pages for all nav entries
- Update home page with accurate status and section links
```
