docs: Complete Phase 6 notebooks and Phase 7 documentation review

Phase 6 - Jupyter Notebooks (15 total):
- Overview tab: livability_choropleth, top_bottom_10_bar, income_safety_scatter
- Housing tab: affordability_choropleth, rent_trend_line, tenure_breakdown_bar
- Safety tab: crime_rate_choropleth, crime_breakdown_bar, crime_trend_line
- Demographics tab: income_choropleth, age_distribution, population_density_bar
- Amenities tab: amenity_index_choropleth, amenity_radar, transit_accessibility_bar

Phase 7 - Documentation:
- Updated CLAUDE.md with Sprint 9 completion status
- Added notebooks directory to application structure
- Expanded figures directory listing

Closes #71, #72, #73, #74, #75, #76, #77

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -6,8 +6,8 @@ Working context for Claude Code on the Analytics Portfolio project.
 
 ## Project Status
 
-**Current Sprint**: 9 (Neighbourhood Dashboard Transition)
-**Phase**: Toronto Neighbourhood Dashboard
+**Current Sprint**: 9 (Neighbourhood Dashboard Transition) - **COMPLETE**
+**Phase**: Toronto Neighbourhood Dashboard - Phase 6 & 7 Done
 **Branch**: `development` (feature branches merge here)
 
 ---
@@ -129,8 +129,12 @@ portfolio_app/
 │   └── time_slider.py       # Time range selector
 ├── figures/                 # Shared chart factories
 │   ├── choropleth.py        # Map visualizations
-│   ├── summary_cards.py     # KPI figures
-│   └── time_series.py       # Trend charts
+│   ├── bar_charts.py        # Ranking, stacked, horizontal bars
+│   ├── scatter.py           # Scatter and bubble plots
+│   ├── radar.py             # Radar/spider charts
+│   ├── demographics.py      # Age pyramids, donut charts
+│   ├── time_series.py       # Trend lines
+│   └── summary_cards.py     # KPI figures
 ├── content/                 # Markdown content
 │   └── blog/                # Blog articles
 ├── toronto/                 # Toronto data logic
@@ -142,6 +146,14 @@ portfolio_app/
 ├── utils/                   # Utilities
 │   └── markdown_loader.py   # Markdown processing
 └── errors/
+
+notebooks/                   # Data documentation (Phase 6)
+├── README.md                # Template and usage guide
+├── overview/                # Overview tab notebooks (3)
+├── housing/                 # Housing tab notebooks (3)
+├── safety/                  # Safety tab notebooks (3)
+├── demographics/            # Demographics tab notebooks (3)
+└── amenities/               # Amenities tab notebooks (3)
 ```
 
 ### URL Routing