feat(psa): add PSAResource, TicketCreatePayload types and abstract provider methods

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

backend/app/services/psa/base.py

@@ -14,6 +14,9 @@ from .types import (
     PSATimeEntry,
     PSABoard,
     PaginatedTicketResult,
+    PSAResource,
+    PSACreatedTicket,
+    TicketCreatePayload,
 )
 
 
@@ -84,3 +87,23 @@ class PSAProvider(ABC):
         work_type: str | None = None,
     ) -> PSATimeEntry:
         ...
+
+    @abstractmethod
+    async def list_resources(self, ticket_id: int) -> list[PSAResource]:
+        ...
+
+    @abstractmethod
+    async def add_resource(self, ticket_id: int, member_id: int) -> PSAResource:
+        ...
+
+    @abstractmethod
+    async def remove_resource(self, ticket_id: int, member_id: int) -> None:
+        ...
+
+    @abstractmethod
+    async def create_ticket(self, payload: TicketCreatePayload) -> PSACreatedTicket:
+        ...
+
+    @abstractmethod
+    async def list_priorities(self) -> list[dict]:
+        ...