misc doc updates

inire/router/pathfinder.py

@@ -25,11 +25,26 @@ class RoutingResult:
 class PathFinder:
     """Multi-net router using Negotiated Congestion."""
 
-    def __init__(self, router: AStarRouter, cost_evaluator: CostEvaluator) -> None:
+    def __init__(
+        self,
+        router: AStarRouter,
+        cost_evaluator: CostEvaluator,
+        max_iterations: int = 10,
+        base_congestion_penalty: float = 100.0,
+    ) -> None:
+        """
+        Initialize the PathFinder.
+
+        Args:
+            router: The A* search engine.
+            cost_evaluator: The evaluator for path costs.
+            max_iterations: Maximum number of rip-up and reroute iterations.
+            base_congestion_penalty: Starting penalty for overlaps.
+        """
         self.router = router
         self.cost_evaluator = cost_evaluator
-        self.max_iterations = 10
-        self.base_congestion_penalty = 100.0
+        self.max_iterations = max_iterations
+        self.base_congestion_penalty = base_congestion_penalty
 
     def route_all(self, netlist: dict[str, tuple[Port, Port]], net_widths: dict[str, float]) -> dict[str, RoutingResult]:
         """Route all nets in the netlist using Negotiated Congestion."""

inire/tests/test_congestion.py

@@ -40,8 +40,8 @@ def test_astar_sbend(basic_evaluator: CostEvaluator) -> None:
 
 def test_pathfinder_negotiated_congestion_resolution(basic_evaluator: CostEvaluator) -> None:
     router = AStarRouter(basic_evaluator)
-    pf = PathFinder(router, basic_evaluator)
-    pf.max_iterations = 10
+    # Increase base penalty to force detour immediately
+    pf = PathFinder(router, basic_evaluator, max_iterations=10, base_congestion_penalty=1000.0)
 
     netlist = {
         "net1": (Port(0, 0, 0), Port(50, 0, 0)),
@@ -57,9 +57,6 @@ def test_pathfinder_negotiated_congestion_resolution(basic_evaluator: CostEvalua
     basic_evaluator.collision_engine.add_static_obstacle(obs_bottom)
     basic_evaluator.danger_map.precompute([obs_top, obs_bottom])
 
-    # Increase base penalty to force detour immediately
-    pf.base_congestion_penalty = 1000.0
-
     results = pf.route_all(netlist, net_widths)
 
     assert results["net1"].is_valid