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/dsn/test_reader.py

@@ -6,10 +6,10 @@ from pathlib import Path
 
 import pytest
 
-from freeroute.dsn import parse_dsn
-from freeroute.dsn.reader import DsnParseError
-from freeroute.dsn.shapes import Circle, Rectangle
-from freeroute.dsn.shapes import Path as DsnPath
+from rpmroute.dsn import parse_dsn
+from rpmroute.dsn.reader import DsnParseError
+from rpmroute.dsn.shapes import Circle, Rectangle
+from rpmroute.dsn.shapes import Path as DsnPath
 
 FIXTURES = Path(__file__).parent / "fixtures"