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_exact_router.py

@@ -15,12 +15,12 @@ import sys
 
 import pytest
 
-from freeroute.board import ShapeSearchTree, TreeShape, build_board
-from freeroute.dsn import parse_dsn
-from freeroute.dsn.sexp import parse
-from freeroute.geometry import IntBox, Polyline, PolylineShape
-from freeroute.route import route, route_dsn_board, route_dsn_board_exact
-from freeroute.route.pipeline import _rule_clearance_dsn, _rule_width_dsn
+from rpmroute.board import ShapeSearchTree, TreeShape, build_board
+from rpmroute.dsn import parse_dsn
+from rpmroute.dsn.sexp import parse
+from rpmroute.geometry import IntBox, Polyline, PolylineShape
+from rpmroute.route import route, route_dsn_board, route_dsn_board_exact
+from rpmroute.route.pipeline import _rule_clearance_dsn, _rule_width_dsn
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))