feat: reduce Patient Pathways to Icicle + Sankey tabs only (Task 10.5)

Removed 6 chart tabs (Market Share, Cost Effectiveness, Cost Waterfall,
Dosing, Heatmap, Duration) from the Patient Pathways tab bar. These will
reappear in the Trust Comparison dashboard (Task 10.8).

All _render_* helper functions preserved in chart.py for reuse.

dash_app/callbacks/chart.py

@@ -1,4 +1,10 @@
-"""Callbacks for tab switching, pathway data loading, and chart rendering."""
+"""Callbacks for tab switching, pathway data loading, and chart rendering.
+
+NOTE: The _render_* helper functions for all 8 chart types are preserved here.
+Patient Pathways view uses only icicle + sankey tabs. The remaining 6 chart
+renderers (_render_market_share, _render_cost_waterfall, etc.) will be reused
+by the Trust Comparison dashboard in Task 10.8.
+"""
 import logging
 
 from dash import Input, Output, State, ctx, no_update
@@ -8,7 +14,7 @@ from dash_app.components.chart_card import TAB_DEFINITIONS
 
 log = logging.getLogger(__name__)
 
-# Tab IDs for callback inputs
+# Tab IDs for callback inputs — matches Patient Pathways tab bar (2 tabs)
 _TAB_IDS = [f"tab-{tab_id}" for tab_id, _ in TAB_DEFINITIONS]
 
 

dash_app/components/chart_card.py

@@ -2,7 +2,14 @@
 from dash import html, dcc
 
 
+# Patient Pathways view: only Icicle + Sankey
 TAB_DEFINITIONS = [
+    ("icicle", "Icicle"),
+    ("sankey", "Sankey"),
+]
+
+# Full set retained for Trust Comparison dashboard (Phase 10.8)
+ALL_TAB_DEFINITIONS = [
     ("icicle", "Icicle"),
     ("market-share", "Market Share"),
     ("cost-effectiveness", "Cost Effectiveness"),
@@ -18,7 +25,7 @@ def make_chart_card():
     """Return a chart card with tab bar and dcc.Graph.
 
     Contains:
-    - Tab bar with 8 chart tabs (Icicle active by default)
+    - Tab bar with 2 chart tabs (Icicle active by default, Sankey)
     - Header with title and dynamic subtitle
     - dcc.Loading wrapper around dcc.Graph for loading spinner
     """