Refactor documentation and diagrams for web/pipeline. (#272)

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com> for assistance with diagram creation and documentation prose updates.

docs/index.md

@@ -0,0 +1,33 @@
+---
+title: The Biergarten App
+last-updated: 2026-08-31
+tags:
+  - overview
+  - index
+---
+
+Welcome to the documentation for The Biergarten App.
+
+## Documentation Sections
+
+- **[Architecture](web/architecture.md)** — System design and components
+- **[Website](web/getting-started.md)** — Backend and frontend documentation
+- **[Pipeline](pipeline/README.md)** — Data generation pipeline
+
+## AI Disclosure
+
+Parts of this documentation are drafted and maintained with AI assistance
+(Claude, Sonnet or Opus, via Claude Code), including prose (architecture
+notes, guides) and diagrams (the Mermaid sources under `diagrams/`).
+AI-authored changes are reviewed by a maintainer before merging, same as any
+other contribution.
+
+Staleness checks are partly automated too, to guard against doc-rot: the
+repo's `doc-drift-web` and `doc-drift-pipeline` Claude Code skills
+(`.claude/skills/`) diff recent code changes against these docs and flag
+claims that may need updating.
+
+This is separate from the pipeline's own use of AI to *generate seed data*
+(brewery names, descriptions, user profiles) — see
+[ETHICS-AND-KNOWN-ISSUES.md](pipeline/ETHICS-AND-KNOWN-ISSUES.md) for that
+disclosure.