K7: add cashbook service interfaces

- IBookingCategoryService: CRUD + EnsureSystemCategories
- ICashBookService: entries, balance, report, membership fees

docs/IMPLEMENTATION_PLAN.md

@@ -1705,7 +1705,7 @@ public enum CashBookEntryType { Income = 0, Expense = 1 }
 | ✓ | K4 | Security | Kassenwart Role + Policy | 4 |
 | ✓ | K5 | Infrastructure | Repositories | 5 |
 | ✓ | K6 | Application | DTOs | 3 |
-| ☐ | K7 | Application | Service Interfaces | 2 |
+| ✓ | K7 | Application | Service Interfaces | 2 |
 | ☐ | K8 | Application | Service Implementations | 4 |
 | ☐ | K9 | Application | Category Seeder | 1 |
 | ☐ | K10 | Application | Day Close Integration | 1 |

src/Koogle.Application/Interfaces/IBookingCategoryService.cs

@@ -0,0 +1,55 @@
+using Koogle.Application.DTOs;
+
+namespace Koogle.Application.Interfaces;
+
+/// <summary>
+/// Service interface for managing booking category operations.
+/// </summary>
+public interface IBookingCategoryService
+{
+    /// <summary>
+    /// Retrieves all booking categories for the current club context.
+    /// </summary>
+    /// <param name="includeInactive">Whether to include inactive categories.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A list of booking categories.</returns>
+    Task<List<BookingCategoryDto>> GetAllAsync(bool includeInactive = false, CancellationToken ct = default);
+
+    /// <summary>
+    /// Retrieves a booking category by its unique identifier.
+    /// </summary>
+    /// <param name="id">The unique identifier of the category.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The category if found; otherwise, null.</returns>
+    Task<BookingCategoryDto?> GetByIdAsync(Guid id, CancellationToken ct = default);
+
+    /// <summary>
+    /// Creates a new booking category in the current club context.
+    /// </summary>
+    /// <param name="dto">The category creation data.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The created category.</returns>
+    Task<BookingCategoryDto> CreateAsync(CreateBookingCategoryDto dto, CancellationToken ct = default);
+
+    /// <summary>
+    /// Updates an existing booking category.
+    /// </summary>
+    /// <param name="dto">The category update data.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The updated category.</returns>
+    Task<BookingCategoryDto> UpdateAsync(UpdateBookingCategoryDto dto, CancellationToken ct = default);
+
+    /// <summary>
+    /// Deletes a booking category (soft delete).
+    /// </summary>
+    /// <param name="id">The unique identifier of the category to delete.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>True if deleted successfully; otherwise, false.</returns>
+    Task<bool> DeleteAsync(Guid id, CancellationToken ct = default);
+
+    /// <summary>
+    /// Ensures system categories exist for the current club.
+    /// </summary>
+    /// <param name="ct">Cancellation token.</param>
+    Task EnsureSystemCategoriesAsync(CancellationToken ct = default);
+}

src/Koogle.Application/Interfaces/ICashBookService.cs

@@ -0,0 +1,92 @@
+using Koogle.Application.DTOs;
+
+namespace Koogle.Application.Interfaces;
+
+/// <summary>
+/// Service interface for managing cash book operations.
+/// </summary>
+public interface ICashBookService
+{
+    /// <summary>
+    /// Retrieves cash book entries for the current club within optional date range.
+    /// </summary>
+    /// <param name="from">Optional start date filter.</param>
+    /// <param name="to">Optional end date filter.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A list of cash book entries.</returns>
+    Task<List<CashBookEntryDto>> GetEntriesAsync(DateTime? from = null, DateTime? to = null, CancellationToken ct = default);
+
+    /// <summary>
+    /// Retrieves a cash book entry by its unique identifier.
+    /// </summary>
+    /// <param name="id">The unique identifier of the entry.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The entry if found; otherwise, null.</returns>
+    Task<CashBookEntryDto?> GetByIdAsync(Guid id, CancellationToken ct = default);
+
+    /// <summary>
+    /// Creates a new cash book entry in the current club context.
+    /// </summary>
+    /// <param name="dto">The entry creation data.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The created entry.</returns>
+    Task<CashBookEntryDto> CreateAsync(CreateCashBookEntryDto dto, CancellationToken ct = default);
+
+    /// <summary>
+    /// Updates an existing cash book entry.
+    /// </summary>
+    /// <param name="dto">The entry update data.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The updated entry.</returns>
+    Task<CashBookEntryDto> UpdateAsync(UpdateCashBookEntryDto dto, CancellationToken ct = default);
+
+    /// <summary>
+    /// Deletes a cash book entry (soft delete).
+    /// </summary>
+    /// <param name="id">The unique identifier of the entry to delete.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>True if deleted successfully; otherwise, false.</returns>
+    Task<bool> DeleteAsync(Guid id, CancellationToken ct = default);
+
+    /// <summary>
+    /// Gets the current balance for the club.
+    /// </summary>
+    /// <param name="asOfDate">Optional date to calculate balance as of.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The current balance.</returns>
+    Task<decimal> GetBalanceAsync(DateTime? asOfDate = null, CancellationToken ct = default);
+
+    /// <summary>
+    /// Generates a cash book report for a date range.
+    /// </summary>
+    /// <param name="from">Report start date.</param>
+    /// <param name="to">Report end date.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The cash book report.</returns>
+    Task<CashBookReportDto> GetReportAsync(DateTime from, DateTime to, CancellationToken ct = default);
+
+    /// <summary>
+    /// Retrieves cash book entries linked to a specific day.
+    /// </summary>
+    /// <param name="dayId">The day identifier.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A list of entries for the day.</returns>
+    Task<List<CashBookEntryDto>> GetByDayIdAsync(Guid dayId, CancellationToken ct = default);
+
+    /// <summary>
+    /// Creates membership fee entries for all active members.
+    /// </summary>
+    /// <param name="dto">The membership fee creation data.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>The list of created entries.</returns>
+    Task<List<CashBookEntryDto>> CreateMembershipFeesAsync(CreateMembershipFeesDto dto, CancellationToken ct = default);
+
+    /// <summary>
+    /// Checks if membership fees already exist for a specific month.
+    /// </summary>
+    /// <param name="year">The year.</param>
+    /// <param name="month">The month.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>True if fees exist; otherwise, false.</returns>
+    Task<bool> MembershipFeesExistAsync(int year, int month, CancellationToken ct = default);
+}