refactor: restructure sidebar with chart views, remove placeholder items (Task 7.3)

- Remove non-functional sidebar items: Cost Analysis, Export Data
- Remove filter trigger items: Drug/Trust/Directory Selection, Indications
- Add Chart Views section: Icicle Chart (active), Sankey Diagram (disabled), Timeline (disabled)
- Remove tab row from chart_card.py (chart view selection now in sidebar)
- Remove open_drawer callback (sidebar no longer has filter triggers)
- Add .sidebar__item--disabled CSS class

dash_app/components/sidebar.py

@@ -5,11 +5,7 @@ from dash import html
 
 
 def _svg_icon(svg_body):
-    """Wrap an SVG body string into an html.Img using a data URI.
-
-    This avoids needing dash-svg or dangerouslySetInnerHTML.
-    The SVG icons are copied from 01_nhs_classic.html.
-    """
+    """Wrap an SVG body string into an html.Img using a data URI."""
     svg = (
         f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" '
         f'fill="none" stroke="currentColor" stroke-width="2">{svg_body}</svg>'
@@ -20,15 +16,12 @@ def _svg_icon(svg_body):
     )
 
 
-# SVG icon bodies from 01_nhs_classic.html
+# SVG icon bodies (Feather-style)
 _ICONS = {
     "pathway": '<rect x="3" y="3" width="7" height="7"/><rect x="14" y="3" width="7" height="7"/><rect x="14" y="14" width="7" height="7"/><rect x="3" y="14" width="7" height="7"/>',
-    "drug": '<circle cx="12" cy="12" r="3"/><path d="M19.4 15a1.65 1.65 0 00.33 1.82l.06.06a2 2 0 010 2.83 2 2 0 01-2.83 0l-.06-.06a1.65 1.65 0 00-1.82-.33 1.65 1.65 0 00-1 1.51V21a2 2 0 01-4 0v-.09A1.65 1.65 0 009 19.4a1.65 1.65 0 00-1.82.33l-.06.06a2 2 0 01-2.83 0 2 2 0 010-2.83l.06-.06A1.65 1.65 0 004.68 15a1.65 1.65 0 00-1.51-1H3a2 2 0 010-4h.09A1.65 1.65 0 004.6 9a1.65 1.65 0 00-.33-1.82l-.06-.06a2 2 0 012.83-2.83l.06.06A1.65 1.65 0 009 4.68a1.65 1.65 0 001-1.51V3a2 2 0 014 0v.09a1.65 1.65 0 001 1.51 1.65 1.65 0 001.82-.33l.06-.06a2 2 0 012.83 2.83l-.06.06A1.65 1.65 0 0019.4 9a1.65 1.65 0 001.51 1H21a2 2 0 010 4h-.09a1.65 1.65 0 00-1.51 1z"/>',
-    "trust": '<path d="M3 9l9-7 9 7v11a2 2 0 01-2 2H5a2 2 0 01-2-2z"/>',
-    "directory": '<path d="M22 19a2 2 0 01-2 2H4a2 2 0 01-2-2V5a2 2 0 012-2h5l2 3h9a2 2 0 012 2z"/>',
-    "indication": '<path d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8z"/><polyline points="14,2 14,8 20,8"/>',
-    "cost": '<line x1="18" y1="20" x2="18" y2="10"/><line x1="12" y1="20" x2="12" y2="4"/><line x1="6" y1="20" x2="6" y2="14"/>',
-    "export": '<path d="M21 15v4a2 2 0 01-2 2H5a2 2 0 01-2-2v-4"/><polyline points="7 10 12 15 17 10"/><line x1="12" y1="15" x2="12" y2="3"/>',
+    "icicle": '<rect x="3" y="3" width="18" height="4" rx="1"/><rect x="3" y="10" width="10" height="4" rx="1"/><rect x="3" y="17" width="6" height="4" rx="1"/>',
+    "sankey": '<path d="M6 3v18"/><path d="M18 3v18"/><path d="M6 8c6 0 6 5 12 5"/><path d="M6 16c4 0 4-3 12-3"/>',
+    "timeline": '<line x1="3" y1="12" x2="21" y2="12"/><circle cx="6" cy="12" r="2"/><circle cx="12" cy="12" r="2"/><circle cx="18" cy="12" r="2"/>',
 }
 
 
@@ -38,31 +31,22 @@ def make_sidebar():
         className="sidebar",
         **{"aria-label": "Main navigation"},
         children=[
-            # Analysis section
+            # Overview section
             html.Div(
                 className="sidebar__section",
                 children=[
-                    html.Div("Analysis", className="sidebar__label"),
+                    html.Div("Overview", className="sidebar__label"),
                     _sidebar_item("Pathway Overview", "pathway", active=True),
-                    _sidebar_item(
-                        "Drug Selection", "drug", item_id="sidebar-drug-selection"
-                    ),
-                    _sidebar_item(
-                        "Trust Selection", "trust", item_id="sidebar-trust-selection"
-                    ),
-                    _sidebar_item("Directory Selection", "directory"),
-                    _sidebar_item(
-                        "Indications", "indication", item_id="sidebar-indications"
-                    ),
                 ],
             ),
-            # Reports section
+            # Chart views section
             html.Div(
                 className="sidebar__section",
                 children=[
-                    html.Div("Reports", className="sidebar__label"),
-                    _sidebar_item("Cost Analysis", "cost"),
-                    _sidebar_item("Export Data", "export"),
+                    html.Div("Chart Views", className="sidebar__label"),
+                    _sidebar_item("Icicle Chart", "icicle", active=True),
+                    _sidebar_item("Sankey Diagram", "sankey", disabled=True),
+                    _sidebar_item("Timeline", "timeline", disabled=True),
                 ],
             ),
             # Footer
@@ -78,11 +62,13 @@ def make_sidebar():
     )
 
 
-def _sidebar_item(label, icon_key, active=False, item_id=None):
+def _sidebar_item(label, icon_key, active=False, disabled=False, item_id=None):
     """Create a single sidebar navigation item."""
     class_name = "sidebar__item"
     if active:
         class_name += " sidebar__item--active"
+    if disabled:
+        class_name += " sidebar__item--disabled"
 
     props = {"className": class_name}
     if item_id: