- Create src/data_processing/parsing.py with parse_average_spacing(),
parse_pathway_drugs(), and calculate_retention_rate()
- Add 8-tab bar to chart_card.py (Icicle, Market Share, Cost Effectiveness,
Cost Waterfall, Sankey, Dosing, Heatmap, Duration)
- Add active-tab dcc.Store and tab switching callback in chart.py
- Remove Chart Views section from sidebar (now in tab bar)
- Lazy rendering: only active tab's chart is computed
- header.py: NHS branded top bar with logo, title, breadcrumb,
data freshness indicators (record count + last updated with IDs
for callback updates)
- sidebar.py: Navigation with 7 items across Analysis/Reports
sections, SVG icons via data URI, Drug Selection and Indications
items have IDs for drawer open callbacks (Phase 4)
- app.py: Assembles header + sidebar + main content placeholder
- nhs.css: Added .sidebar__icon rule for img-based SVG icons