Fix: Update permission names, models and constants

Permission renames:
- BOOK_APPOINTMENT -> CREATE_EXCHANGE
- VIEW_OWN_APPOINTMENTS -> VIEW_OWN_EXCHANGES
- CANCEL_OWN_APPOINTMENT -> CANCEL_OWN_EXCHANGE
- VIEW_ALL_APPOINTMENTS -> VIEW_ALL_EXCHANGES
- CANCEL_ANY_APPOINTMENT -> CANCEL_ANY_EXCHANGE
- Add COMPLETE_EXCHANGE permission

Model changes:
- Delete AppointmentStatus enum
- Delete Appointment model

Schema changes:
- Delete BookingRequest (was for old booking)
- Delete AppointmentResponse, PaginatedAppointments
- Delete BookableSlot, AvailableSlotsResponse (unused)

Constants changes:
- Remove appointmentStatuses from shared/constants.json
- Merge booking constants into exchange section
- Update shared_constants.py and validate_constants.py

backend/routes/exchange.py

@@ -180,7 +180,7 @@ def _to_exchange_response(
 @router.get("/price", response_model=ExchangePriceResponse)
 async def get_exchange_price(
     db: AsyncSession = Depends(get_db),
-    _current_user: User = Depends(require_permission(Permission.BOOK_APPOINTMENT)),
+    _current_user: User = Depends(require_permission(Permission.CREATE_EXCHANGE)),
 ) -> ExchangePriceResponse:
     """
     Get the current BTC/EUR price for trading.
@@ -275,7 +275,7 @@ async def get_exchange_price(
 async def create_exchange(
     request: ExchangeRequest,
     db: AsyncSession = Depends(get_db),
-    current_user: User = Depends(require_permission(Permission.BOOK_APPOINTMENT)),
+    current_user: User = Depends(require_permission(Permission.CREATE_EXCHANGE)),
 ) -> ExchangeResponse:
     """
     Create a new exchange trade booking.
@@ -415,7 +415,7 @@ trades_router = APIRouter(prefix="/api/trades", tags=["trades"])
 @trades_router.get("", response_model=list[ExchangeResponse])
 async def get_my_trades(
     db: AsyncSession = Depends(get_db),
-    current_user: User = Depends(require_permission(Permission.VIEW_OWN_APPOINTMENTS)),
+    current_user: User = Depends(require_permission(Permission.VIEW_OWN_EXCHANGES)),
 ) -> list[ExchangeResponse]:
     """Get the current user's exchanges, sorted by date (newest first)."""
     result = await db.execute(
@@ -432,7 +432,7 @@ async def get_my_trades(
 async def cancel_my_trade(
     exchange_id: int,
     db: AsyncSession = Depends(get_db),
-    current_user: User = Depends(require_permission(Permission.CANCEL_OWN_APPOINTMENT)),
+    current_user: User = Depends(require_permission(Permission.CANCEL_OWN_EXCHANGE)),
 ) -> ExchangeResponse:
     """Cancel one of the current user's exchanges."""
     # Get the exchange with eager loading of user relationship
@@ -512,7 +512,7 @@ def _to_admin_exchange_response(exchange: Exchange) -> AdminExchangeResponse:
 @admin_trades_router.get("/upcoming", response_model=list[AdminExchangeResponse])
 async def get_upcoming_trades(
     db: AsyncSession = Depends(get_db),
-    _current_user: User = Depends(require_permission(Permission.VIEW_ALL_APPOINTMENTS)),
+    _current_user: User = Depends(require_permission(Permission.VIEW_ALL_EXCHANGES)),
 ) -> list[AdminExchangeResponse]:
     """Get all upcoming booked trades, sorted by slot time ascending."""
     now = datetime.now(UTC)
@@ -539,7 +539,7 @@ async def get_past_trades(
     end_date: date | None = None,
     user_search: str | None = None,
     db: AsyncSession = Depends(get_db),
-    _current_user: User = Depends(require_permission(Permission.VIEW_ALL_APPOINTMENTS)),
+    _current_user: User = Depends(require_permission(Permission.VIEW_ALL_EXCHANGES)),
 ) -> list[AdminExchangeResponse]:
     """
     Get past trades with optional filters.
@@ -599,9 +599,7 @@ async def get_past_trades(
 async def complete_trade(
     exchange_id: int,
     db: AsyncSession = Depends(get_db),
-    _current_user: User = Depends(
-        require_permission(Permission.CANCEL_ANY_APPOINTMENT)
-    ),
+    _current_user: User = Depends(require_permission(Permission.CANCEL_ANY_EXCHANGE)),
 ) -> AdminExchangeResponse:
     """Mark a trade as completed. Only possible after slot time has passed."""
 
@@ -647,9 +645,7 @@ async def complete_trade(
 async def mark_no_show(
     exchange_id: int,
     db: AsyncSession = Depends(get_db),
-    _current_user: User = Depends(
-        require_permission(Permission.CANCEL_ANY_APPOINTMENT)
-    ),
+    _current_user: User = Depends(require_permission(Permission.CANCEL_ANY_EXCHANGE)),
 ) -> AdminExchangeResponse:
     """Mark a trade as no-show. Only possible after slot time has passed."""
 
@@ -693,9 +689,7 @@ async def mark_no_show(
 async def admin_cancel_trade(
     exchange_id: int,
     db: AsyncSession = Depends(get_db),
-    _current_user: User = Depends(
-        require_permission(Permission.CANCEL_ANY_APPOINTMENT)
-    ),
+    _current_user: User = Depends(require_permission(Permission.CANCEL_ANY_EXCHANGE)),
 ) -> AdminExchangeResponse:
     """Cancel any trade (admin only)."""