Implement interactive prop handling for StickmanRig

- Added PropTrajectory class for deterministic ballistic calculations.
- Introduced StickmanPropInteraction component to manage prop interactions (pickup, drop, throw).
- Implemented grip resolution and attachment logic for props.
- Added signals for interaction events (prop_picked_up, prop_dropped, prop_thrown).
- Defined specifications for prop interaction lifecycle and event rules.
- Ensured compatibility with existing prop systems and added new capabilities for prop pickup.

scripts/action_registry.gd

@@ -47,6 +47,9 @@ const ACTION_TEMPLATES := {
 		"params": [],
 		"reactive_role": ReactiveRole.TAKEOVER, "overlay_eligible": false,
 	},
+	"pick_up_prop": { "label": "Pick Up Prop", "icon": "🖐️", "params": [{"key": "target_prop", "type": "prop", "required": true}, {"key": "hand", "type": "hand", "default": "auto"}], "reactive_role": ReactiveRole.SEQUENTIAL, "overlay_eligible": false },
+	"drop_prop": { "label": "Drop Prop", "icon": "⬇️", "params": [], "reactive_role": ReactiveRole.SEQUENTIAL, "overlay_eligible": false },
+	"throw_prop": { "label": "Throw Prop", "icon": "🎯", "params": [{"key": "target_prop", "type": "prop", "required": true}, {"key": "target_position", "type": "position", "required": true}, {"key": "flight_time", "type": "float", "default": 0.9}], "reactive_role": ReactiveRole.SEQUENTIAL, "overlay_eligible": false },
 }
 
 
@@ -102,6 +105,10 @@ static func to_rule_action(action: Dictionary, target_id: int) -> Dictionary:
 				params["stop_current"] = true
 		"wait":
 			params["duration"] = float(action.get("duration", 0.0))
+		"pick_up_prop":
+			params["target_prop"] = int(action.get("target_prop", -1)); params["hand"] = String(action.get("hand", "auto"))
+		"throw_prop":
+			params["target_prop"] = int(action.get("target_prop", -1)); params["target_position"] = action.get("target_position", Vector2.ZERO); params["flight_time"] = float(action.get("flight_time", 0.9))
 	return {
 		"type": String(action.get("type", "")),
 		"target": target_id,
@@ -126,6 +133,9 @@ static func from_rule_action(rule_action: Dictionary) -> Dictionary:
 			return speak
 		"wait":
 			return { "type": "wait", "duration": float(params.get("duration", 0.0)) }
+		"pick_up_prop": return {"type": "pick_up_prop", "target_prop": int(params.get("target_prop", -1)), "hand": String(params.get("hand", "auto"))}
+		"drop_prop": return {"type": "drop_prop"}
+		"throw_prop": return {"type": "throw_prop", "target_prop": int(params.get("target_prop", -1)), "target_position": params.get("target_position", Vector2.ZERO), "flight_time": float(params.get("flight_time", 0.9))}
 		_:
 			return { "type": String(rule_action.get("type", "")) }
 
@@ -155,6 +165,9 @@ static func summarize(action: Dictionary) -> String:
 			return "Ragdoll"
 		"recover":
 			return "Recover"
+		"pick_up_prop": return "Pick Up Prop"
+		"drop_prop": return "Drop Prop"
+		"throw_prop": return "Throw Prop"
 		_:
 			return type