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/geometry/test_point_vector.py

@@ -8,7 +8,7 @@ Java ``long``, and rational equality.
 
 from __future__ import annotations
 
-from freeroute.geometry import (
+from rpmroute.geometry import (
     IntPoint,
     IntVector,
     RationalPoint,
@@ -139,7 +139,7 @@ def test_rational_point_infinite():
 
 
 def test_rational_point_contained_in_box_exact():
-    from freeroute.geometry import IntBox
+    from rpmroute.geometry import IntBox
 
     box = IntBox(0, 0, 2, 2)
     assert RationalPoint(3, 2, 2).is_contained_in(box)  # (1.5, 1.0) inside