feat(rules): allow a move action in place of a standard action

PF1e CRB (Actions in Combat): a move action can be taken instead of the
standard one. The budget filter now converts a second move action onto
the standard slot when the move slot is spent and the standard is still
free, so (move, stand_up) and (move, move) are legal; a third move (or
any further standard) is still surplus. The greedy walk is expressed
with a spent-slot map to stay inside the C901 complexity ceiling.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/pf1e_simulator/combat.py

@@ -5900,32 +5900,38 @@ def _action_economy_filter(actions: tuple[Action, ...]) -> tuple[Action, ...]:
     Greedy in-order walk: each action is kept while its budget slot is free
     (one standard, one move, one swift; a full-round action is only legal
     while BOTH the standard and the move slot are still free and consumes
-    them all). The kept sequence is therefore the earliest order-stable legal
+    them all). PF1e (CRB, "Actions in Combat"): a move action can be taken
+    "instead of" the standard one — when the move slot is already spent and
+    the standard slot is still free, a further move action converts the
+    standard slot (so (move, stand_up) and (move, move) are legal). The kept
+    sequence is therefore the earliest order-stable legal
     prefix-subsequence; every skipped action is deterministic.
     """
     kept: list[Action] = []
-    standard_used = False
-    move_used = False
-    swift_used = False
+    spent: dict[_ActionEconomySlot, bool] = {
+        "standard": False,
+        "move": False,
+        "swift": False,
+        "full_round": False,
+        "free": False,
+    }
     for action in actions:
         slot = _action_economy_slot(action.kind)
-        if slot == "standard":
-            if standard_used:
+        if slot == "free":
+            kept.append(action)
+            continue
+        if slot == "full_round":
+            if spent["standard"] or spent["move"]:
                 continue
-            standard_used = True
-        elif slot == "move":
-            if move_used:
-                continue
-            move_used = True
-        elif slot == "swift":
-            if swift_used:
-                continue
-            swift_used = True
-        elif slot == "full_round":
-            if standard_used or move_used:
-                continue
-            standard_used = True
-            move_used = True
+            spent["standard"] = True
+            spent["move"] = True
+            kept.append(action)
+            continue
+        if slot == "move" and spent["move"]:
+            slot = "standard"  # conversion: a move action consumes the standard slot
+        if spent[slot]:
+            continue
+        spent[slot] = True
         kept.append(action)
     return tuple(kept)