refactor: move services and AITools to MoneyMap.Core

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

MoneyMap.Core/Services/ReferenceDataService.cs

@@ -0,0 +1,81 @@
+using Microsoft.EntityFrameworkCore;
+using MoneyMap.Data;
+using MoneyMap.Models;
+
+namespace MoneyMap.Services;
+
+/// <summary>
+/// Service for retrieving reference/lookup data used in dropdowns and filters.
+/// </summary>
+public interface IReferenceDataService
+{
+    /// <summary>
+    /// Gets all distinct categories from transactions, sorted alphabetically.
+    /// </summary>
+    Task<List<string>> GetAvailableCategoriesAsync();
+
+    /// <summary>
+    /// Gets all merchants, sorted by name.
+    /// </summary>
+    Task<List<Merchant>> GetAvailableMerchantsAsync();
+
+    /// <summary>
+    /// Gets all cards with optional account information included.
+    /// </summary>
+    Task<List<Card>> GetAvailableCardsAsync(bool includeAccount = true);
+
+    /// <summary>
+    /// Gets all accounts, sorted by institution and last4.
+    /// </summary>
+    Task<List<Account>> GetAvailableAccountsAsync();
+}
+
+public class ReferenceDataService : IReferenceDataService
+{
+    private readonly MoneyMapContext _db;
+
+    public ReferenceDataService(MoneyMapContext db)
+    {
+        _db = db;
+    }
+
+    public async Task<List<string>> GetAvailableCategoriesAsync()
+    {
+        return await _db.Transactions
+            .Select(t => t.Category ?? "")
+            .Where(c => !string.IsNullOrWhiteSpace(c))
+            .Distinct()
+            .OrderBy(c => c)
+            .ToListAsync();
+    }
+
+    public async Task<List<Merchant>> GetAvailableMerchantsAsync()
+    {
+        return await _db.Merchants
+            .OrderBy(m => m.Name)
+            .ToListAsync();
+    }
+
+    public async Task<List<Card>> GetAvailableCardsAsync(bool includeAccount = true)
+    {
+        var query = _db.Cards.AsQueryable();
+
+        if (includeAccount)
+        {
+            query = query.Include(c => c.Account);
+        }
+
+        return await query
+            .OrderBy(c => c.Owner)
+            .ThenBy(c => c.Last4)
+            .ToListAsync();
+    }
+
+    public async Task<List<Account>> GetAvailableAccountsAsync()
+    {
+        return await _db.Accounts
+            .OrderBy(a => a.Institution)
+            .ThenBy(a => a.Last4)
+            .ToListAsync();
+    }
+}