numerous improvemts

rota/workers.py

@@ -111,6 +111,9 @@ class Worker(BaseModel):
     bank_holiday_extra: int = 0
     pair: int | str | None = None
     locum: bool = False
+    allowed_multi_shift_sets: list[set] = []  # or list/set of frozensets
+    prefer_multi_shift_together: int = 0  # Default: no preference
+    # Set to a positive integer to prefer, negative to discourage, 0 for neutral
 
     shift_fte_overrides: dict[str, int] = {} # Need checks to ensure shifts exist
 
@@ -389,3 +392,8 @@ class Worker(BaseModel):
             if shift in self.fte_adj_shifts:
                 return self.fte_adj_shifts[shift]
         return self.fte_adj
+
+    def allow_shifts_together(self, *shifts):
+        if not hasattr(self, "allowed_multi_shift_sets"):
+            self.allowed_multi_shift_sets = []
+        self.allowed_multi_shift_sets.append(frozenset(shifts))