Restructured src to more logical heirachy

visualization/CLAUDE.md

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+# visualization/ - Plotly Chart Generation
+
+## Module: plotly_generator.py
+
+Generates interactive Plotly icicle charts for patient pathway hierarchies.
+
+### Key Functions
+
+**create_icicle_figure(ice_df, title)**
+- Builds Plotly icicle figure from pre-processed DataFrame
+- Uses 10-field customdata: value, costpp, cost_pp_pa, first/last seen (node + parent), average_spacing, avg_days
+- Color gradient based on patient volume (darkblue=high, lightblue=low)
+- Hover template shows full treatment pathway and statistics
+
+**save_figure_html(figure, filepath)**
+- Exports interactive HTML file with embedded Plotly.js
+
+**open_figure_in_browser(filepath)**
+- Opens HTML file in default browser
+
+### Data Requirements
+
+Input DataFrame must have columns: parents, ids, labels, value, colour, cost, costpp, cost_pp_pa, first_seen, last_seen, first_seen_parent, last_seen_parent, average_spacing, avg_days
+
+### Output
+
+Interactive icicle chart showing Trust → Directory/Indication → Drug → Pathway hierarchy with rich tooltips.

visualization/__init__.py

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+"""
+Visualization package for patient pathway charts.
+
+This package contains functions for generating interactive Plotly visualizations:
+- plotly_generator: Create icicle charts for patient pathway analysis
+"""
+
+from visualization.plotly_generator import (
+    create_icicle_figure,
+    save_figure_html,
+    open_figure_in_browser,
+)
+
+__all__ = [
+    "create_icicle_figure",
+    "save_figure_html",
+    "open_figure_in_browser",
+]