Implement Phase 5: reconciliation, SignalR notifications, payees, splits & plugins

Add full frontend UI for five backend features: bank reconciliation (3-step
stepper workflow), payee management (CRUD with alias chips), transaction splits
(expandable rows + split editor), plugins (card grid), and real-time SignalR
notifications (bell dropdown with badge). Fix backend PayeeResponse to expose
alias IDs for deletion.

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

src/Purrse.Api/Services/PayeeService.cs

@@ -22,7 +22,7 @@ public class PayeeService : IPayeeService
             .Include(p => p.Aliases).Include(p => p.DefaultCategory)
             .Where(p => p.UserId == userId)
             .OrderBy(p => p.Name)
-            .Select(p => new PayeeResponse(p.Id, p.Name, p.DefaultCategoryId, p.DefaultCategory != null ? p.DefaultCategory.Name : null, p.IsActive, p.Aliases.Select(a => a.Alias).ToList()))
+            .Select(p => new PayeeResponse(p.Id, p.Name, p.DefaultCategoryId, p.DefaultCategory != null ? p.DefaultCategory.Name : null, p.IsActive, p.Aliases.Select(a => new PayeeAliasResponse(a.Id, a.Alias)).ToList()))
             .ToListAsync();
     }
 
@@ -30,7 +30,7 @@ public class PayeeService : IPayeeService
     {
         var p = await _db.Payees.Include(p => p.Aliases).Include(p => p.DefaultCategory)
             .FirstOrDefaultAsync(p => p.Id == payeeId && p.UserId == userId);
-        return p == null ? null : new PayeeResponse(p.Id, p.Name, p.DefaultCategoryId, p.DefaultCategory?.Name, p.IsActive, p.Aliases.Select(a => a.Alias).ToList());
+        return p == null ? null : new PayeeResponse(p.Id, p.Name, p.DefaultCategoryId, p.DefaultCategory?.Name, p.IsActive, p.Aliases.Select(a => new PayeeAliasResponse(a.Id, a.Alias)).ToList());
     }
 
     public async Task<PayeeResponse> CreateAsync(Guid userId, CreatePayeeRequest request)
@@ -51,7 +51,7 @@ public class PayeeService : IPayeeService
 
         _db.Payees.Add(payee);
         await _db.SaveChangesAsync();
-        return new PayeeResponse(payee.Id, payee.Name, payee.DefaultCategoryId, null, true, request.Aliases ?? new());
+        return new PayeeResponse(payee.Id, payee.Name, payee.DefaultCategoryId, null, true, payee.Aliases.Select(a => new PayeeAliasResponse(a.Id, a.Alias)).ToList());
     }
 
     public async Task<PayeeResponse> UpdateAsync(Guid userId, Guid payeeId, UpdatePayeeRequest request)
@@ -65,7 +65,7 @@ public class PayeeService : IPayeeService
         payee.IsActive = request.IsActive;
         await _db.SaveChangesAsync();
 
-        return new PayeeResponse(payee.Id, payee.Name, payee.DefaultCategoryId, null, payee.IsActive, payee.Aliases.Select(a => a.Alias).ToList());
+        return new PayeeResponse(payee.Id, payee.Name, payee.DefaultCategoryId, null, payee.IsActive, payee.Aliases.Select(a => new PayeeAliasResponse(a.Id, a.Alias)).ToList());
     }
 
     public async Task DeleteAsync(Guid userId, Guid payeeId)

src/Purrse.Core/DTOs/PayeeDtos.cs

@@ -3,13 +3,15 @@ namespace Purrse.Core.DTOs;
 public record CreatePayeeRequest(string Name, Guid? DefaultCategoryId, List<string>? Aliases);
 public record UpdatePayeeRequest(string Name, Guid? DefaultCategoryId, bool IsActive);
 
+public record PayeeAliasResponse(Guid Id, string Alias);
+
 public record PayeeResponse(
     Guid Id,
     string Name,
     Guid? DefaultCategoryId,
     string? DefaultCategoryName,
     bool IsActive,
-    List<string> Aliases
+    List<PayeeAliasResponse> Aliases
 );
 
 public record CreatePayeeAliasRequest(string Alias);