feat: add desktop packaging (pywebview + PyInstaller)

- resource_path.py: frozen/dev path resolution for bundled data files
- app_desktop.py: pywebview entry point (Dash in daemon thread)
- app.spec: PyInstaller onedir config with data files and hidden imports
- Updated queries.py, card_browser.py, app.py to use get_resource_path()
- Added pywebview + pyinstaller to project dependencies
- Fixed unresolved merge conflict in .gitignore
- Removed stale 01_nhs_classic.html and AdditionalAnalytics.md

dash_app/app.py

@@ -1,7 +1,10 @@
 """Dash application entry point with layout root and state stores."""
+import sys
+
 from dash import Dash, html, dcc
 import dash_mantine_components as dmc
 
+from core.resource_path import get_resource_path
 from dash_app.components.header import make_header
 from dash_app.components.sub_header import make_sub_header
 from dash_app.components.sidebar import make_sidebar
@@ -12,10 +15,11 @@ from dash_app.components.modals import make_modals
 from dash_app.components.trust_comparison import make_tc_landing, make_tc_dashboard
 from dash_app.components.trends import make_trends_landing, make_trends_detail
 
-app = Dash(
-    __name__,
-    suppress_callback_exceptions=True,
-)
+_app_kwargs = {"suppress_callback_exceptions": True}
+if getattr(sys, "frozen", False):
+    _app_kwargs["assets_folder"] = str(get_resource_path("dash_app/assets"))
+
+app = Dash(__name__, **_app_kwargs)
 
 app.layout = dmc.MantineProvider(
     children=[

dash_app/data/card_browser.py

@@ -9,12 +9,11 @@ Also provides get_all_drugs() for the flat "All Drugs" card.
 
 import csv
 from collections import defaultdict
-from pathlib import Path
 
+from core.resource_path import get_resource_path
 from data_processing.diagnosis_lookup import SEARCH_TERM_MERGE_MAP
 
-DATA_DIR = Path(__file__).resolve().parents[2] / "data"
-DIM_SEARCH_TERM_PATH = DATA_DIR / "DimSearchTerm.csv"
+DIM_SEARCH_TERM_PATH = get_resource_path("data/DimSearchTerm.csv")
 
 
 def build_directorate_tree() -> dict[str, dict[str, list[str]]]:

dash_app/data/queries.py

@@ -5,9 +5,9 @@ Resolves the database path relative to this file's location and delegates
 to the shared functions in src/data_processing/pathway_queries.py.
 """
 
-from pathlib import Path
 from typing import Optional
 
+from core.resource_path import get_resource_path
 from data_processing.pathway_queries import (
     load_initial_data as _load_initial_data,
     load_pathway_nodes as _load_pathway_nodes,
@@ -33,7 +33,7 @@ from data_processing.pathway_queries import (
     get_trend_data as _get_trend_data,
 )
 
-DB_PATH = Path(__file__).resolve().parents[2] / "data" / "pathways.db"
+DB_PATH = get_resource_path("data/pathways.db")
 
 
 def load_initial_data() -> dict: