Rename to rpmroute

The router began as a port of FreeRouting and has grown its own engine
(negotiated congestion, tree nets, exact checks, axis escapes), and
'freeroute' was one letter from the project it no longer follows. The
package, module and command are now rpmroute; the freeroute command stays
as an alias, and the RPMROUTE / RPMROUTE_ORACLE_JAVA variables fall back
to the old FREEROUTE names. Version 2026.10.07. Routing is unchanged: a
PCBench board routes to a byte-identical session either way.

tests/board/test_build.py

@@ -15,9 +15,9 @@ import sys
 
 import pytest
 
-from freeroute.board import BasicBoard, ObstacleArea, Pin, build_board
-from freeroute.dsn import parse_dsn
-from freeroute.geometry import IntPoint
+from rpmroute.board import BasicBoard, ObstacleArea, Pin, build_board
+from rpmroute.dsn import parse_dsn
+from rpmroute.geometry import IntPoint
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
@@ -184,7 +184,7 @@ def test_place_keepout_does_not_block_routing():
 
 
 def test_grid_router_leaves_the_interior_of_a_ring_keepout_open():
-    from freeroute.route.pipeline import route_dsn_board
+    from rpmroute.route.pipeline import route_dsn_board
 
     ring_only = "\n".join(
         line for line in _RING_DSN.splitlines() if "wire_keepout" not in line
@@ -251,7 +251,7 @@ def test_oval_pad_keeps_its_width():
 
 
 def test_via_size_comes_from_the_via_padstack():
-    from freeroute.route.pipeline import _via_half_board
+    from rpmroute.route.pipeline import _via_half_board
 
     assert _via_half_board(parse_dsn(_PAD_DSN), 10) == 3000   # 0.6 mm via, board units
 
@@ -279,7 +279,7 @@ def test_a_keepout_named_rule_area_takes_no_clearance():
 
 
 def _route_channel(name):
-    from freeroute.route.pipeline import build_exact_routing_result
+    from rpmroute.route.pipeline import build_exact_routing_result
 
     return build_exact_routing_result(parse_dsn(_CHANNEL_DSN.format(name=name)), resolution=2)