chore: move website files to web/ folder

CLAUDE.md

@@ -13,13 +13,14 @@ Instructions for Claude Code when working on this project.
   - **Snippets**: localStorage with Phase 0 schema (id, name, created, modified, spec, draftSpec, comment, tags, datasetRefs, meta)
   - **Datasets**: IndexedDB (unlimited size, multi-format: JSON/CSV/TSV/TopoJSON, inline & URL sources)
 - **Structure**: Three resizable panels (snippet library, Monaco editor, live preview) + Dataset Manager modal
-- **No build tools**: Open `index.html` directly in browser (needs local server for IndexedDB)
+- **Deployment**: Web app files in `/web` folder; `/docs` folder contains development documentation only
+- **No build tools**: Open `web/index.html` directly in browser (needs local server for IndexedDB)
 
 ## Current Status
 
-**Completed**: Phases 0-12 (Core functionality + Dataset Management + Advanced Dataset Features)
-**In Progress**: Phase 13 - Polish & UX Refinements (keyboard shortcuts, tooltips, notifications, help documentation)
-**Next**: Complete Phase 13 or move to Phase 14 - Advanced Snippet Features
+**Completed**: Phases 0-13 (Core functionality + Dataset Management + Advanced Dataset Features + Polish & UX Refinements)
+**In Progress**: GitHub Pages deployment preparation
+**Next**: Phase 14 - Advanced Snippet Features or additional refinements
 
 ### Key Features Implemented
 - ✅ Snippet management with draft/published workflow
@@ -37,12 +38,21 @@ Instructions for Claude Code when working on this project.
   - Import/Export datasets with auto-format detection
   - Table preview with type detection (🔢📅🔤✓)
   - On-demand URL preview loading with caching
-- ✅ **Polish & UX Features (Phase 13 - In Progress)**
+- ✅ **Polish & UX Features (Phase 13)**
   - Cross-platform keyboard shortcuts (Cmd/Ctrl+Shift+N, Cmd/Ctrl+K, Cmd/Ctrl+S, Escape)
   - Toast notification system (error, success, warning, info)
   - Comprehensive tooltips on all interactive elements
-  - Enhanced Help modal with 6 sections
+  - Enhanced Help modal with 6 sections (About, Features, Getting Started, Shortcuts, Storage, Privacy)
   - Data persistence warnings
+  - **User Settings System**
+    - Configurable editor options (font size 10-18px, tab size, minimap, word wrap, line numbers)
+    - Performance tuning (render debounce delay 300-3000ms)
+    - Date formatting options (smart/relative, locale, ISO, custom with tokens)
+    - UI theme selection (Light, Dark Experimental)
+  - **Theme System**
+    - Light theme (Windows 2000 classic aesthetic)
+    - Experimental dark theme with CSS variables for theming
+    - Automatic editor theme synchronization with UI theme
 
 See `docs/dev-plan.md` for complete roadmap and technical details.
 - when updating documentation, do not record intermediate changes - write them always as a matter-of-fact information