Make the grid and the exact check agree on rotated pads, shared vias and wide nets

Rotated oval pads were built from padded corners that are not in outline
order, so they fell back to their bounding box; neighbouring boxes of a
rotated socket overlap, and the grid's own-pad exemption opened the
overlap to the pin's net, which the exact check then refused. Pads are now
the convex hull of their corners, the exact tree checks a rotated pad
against that outline, and the grid blocks cells against the same outline.

A via reused by a second connection of its net left that connection with
no claim on the via's footprint, so ripping the first owner freed cells
around a via still on the board. Footprint cells now keep every claimant.

A net class wider than the default was searched as a default trace: its
spread was empty below half a cell, halos were circular while the exact
check compares boxes, and a rip-up route only counted what its centre
crossed. The spread now covers the extra width in whole cells, halos are
square, and rip-up victims include what the spread crosses.

bench/diagnose.py now routes with net-class widths and hole spacing, as
the CLI does.

bench/diagnose.py

@@ -32,8 +32,10 @@ from freeroute.route.exact_router import route_board_exact
 from freeroute.route.grid_router import GridRouter, _ends_of
 from freeroute.route.pipeline import (
     _mm_to_board,
+    _net_widths_board,
     _rule_clearance_dsn,
     _rule_width_dsn,
+    _via_drill_board,
     _via_half_board,
 )
 
@@ -183,7 +185,7 @@ def _flood(router: GridRouter, pin, net_no: int, conns) -> tuple[int, Counter]:
 
 def diagnose(
     dsn_text: str, edge_clearance_mm: float | None, resolution: int = 2, shove: bool = False,
-    access_cost: float = 0.0,
+    access_cost: float = 0.0, hole_to_hole_mm: float = 0.25,
 ) -> dict:
     dsn = parse_dsn(dsn_text)
     names = {i + 1: n.name for i, n in enumerate(dsn.nets)}
@@ -199,6 +201,10 @@ def diagnose(
         resolution=resolution,
         shove=shove,
         access_cost=access_cost,
+        # the product's configuration: net-class widths and hole spacing
+        net_widths=_net_widths_board(dsn, scale),
+        via_drill=_via_drill_board(dsn, scale),
+        hole_to_hole=_mm_to_board(dsn, scale, hole_to_hole_mm) or 0,
     )
     routed = seen["router"]
     best = routed._diag_best
@@ -270,11 +276,12 @@ def main(argv: list[str] | None = None) -> int:
     ap.add_argument("--grid-resolution", type=int, default=2, metavar="K")
     ap.add_argument("--shove", action="store_true", help="as mckicad routes")
     ap.add_argument("--access-cost", type=float, default=0.0)
+    ap.add_argument("--hole-to-hole", type=float, default=0.25, metavar="MM")
     ap.add_argument("--json", type=Path, help="also write the full table here")
     args = ap.parse_args(argv)
 
     report = diagnose(args.dsn.read_text(), args.edge_clearance, args.grid_resolution, args.shove,
-                      args.access_cost)
+                      args.access_cost, args.hole_to_hole)
     for row in report["failures"]:
         extra = ""
         for w in row.get("walled", []):