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/route/test_room_router.py

@@ -13,11 +13,11 @@ import sys
 
 import pytest
 
-from freeroute.board import build_board
-from freeroute.dsn import parse_dsn
-from freeroute.dsn.sexp import parse
-from freeroute.geometry import Polyline
-from freeroute.route import route, route_dsn_board_exact, route_dsn_board_rooms
+from rpmroute.board import build_board
+from rpmroute.dsn import parse_dsn
+from rpmroute.dsn.sexp import parse
+from rpmroute.geometry import Polyline
+from rpmroute.route import route, route_dsn_board_exact, route_dsn_board_rooms
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
@@ -31,7 +31,7 @@ WIDE_DOOR = FIXTURES / "rooms_wide_door.dsn"
 
 
 def _clearance(dsn, scale):
-    from freeroute.route.pipeline import _rule_clearance_dsn
+    from rpmroute.route.pipeline import _rule_clearance_dsn
 
     return round(_rule_clearance_dsn(dsn) * scale)