fix: Set ASPNETCORE_ENVIRONMENT=Development in start.sh

- Backend needs Development environment for /api/dev/reseed endpoint
- Without this, endpoint returns 404 and data seeding fails
- Now automatically seeds full dataset on startup:
  * 448 invoices
  * 167 jobs
  * £134,896.99 outstanding invoices
  * Full dashboard data

Author: FiftyEightSoftware

scripts/start.sh

@@ -39,7 +39,7 @@ start_backend() {
 
   if [ -n "$api_dir" ]; then
     echo -e "${GREEN}Starting backend in $api_dir on http://localhost:${BACKEND_PORT}${NC}"
-    (cd "$api_dir" && ENABLE_DEV_RESEED=true dotnet run --urls "http://localhost:${BACKEND_PORT}") &
+    (cd "$api_dir" && ASPNETCORE_ENVIRONMENT=Development ENABLE_DEV_RESEED=true dotnet run --urls "http://localhost:${BACKEND_PORT}") &
     PIDS+=("$!")
   else
     echo -e "${YELLOW}No backend directory found (api/ or backend/). Skipping backend start.${NC}"