d98cd4fd69
New query functions in src/data_processing/pathway_queries.py: - get_drug_market_share: Level 3 drug nodes grouped by directory - get_pathway_costs: Level 4+ pathway nodes with cost_pp_pa - get_cost_waterfall: Directorate cost per patient from level 3 aggregation - get_drug_transitions: Sankey source/target drug transitions with ordinal line labels - get_dosing_intervals: Parsed average_spacing by trust/directory - get_drug_directory_matrix: Directory x drug pivot with patient/cost metrics - get_treatment_durations: Weighted avg_days by drug within directorates Thin wrappers added in dash_app/data/queries.py for all 7 functions.