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/oracle.py

@@ -1,8 +1,8 @@
 """FreeRouting JAR oracle for behaviour-level validation.
 
-**Dev/test only — not part of the shipped package** (freeroute is Java-free by
+**Dev/test only — not part of the shipped package** (rpmroute is Java-free by
 design). This runs the reference FreeRouting JAR to route a Specctra DSN so that
-freeroute's own output can be diffed against the reference implementation. There
+rpmroute's own output can be diffed against the reference implementation. There
 are no unit-test oracles for FreeRouting's geometry/router, so the oracle is how
 we validate at the behaviour level: same DSN in, compare routed connectivity.
 
@@ -10,7 +10,7 @@ Tests that use this skip automatically when a Java 21+ runtime or the JAR is not
 available (e.g. CI without a JVM), so the normal suite stays Java-free.
 
 Overrides:
-- ``FREEROUTE_ORACLE_JAVA`` — explicit path to a ``java`` binary.
+- ``RPMROUTE_ORACLE_JAVA`` (or the older ``FREEROUTE_ORACLE_JAVA``) — explicit path to a ``java`` binary.
 - ``FREEROUTING_JAR`` — explicit path to a freerouting JAR.
 """
 
@@ -27,7 +27,7 @@ import tempfile
 
 import pytest
 
-from freeroute.dsn.sexp import parse
+from rpmroute.dsn.sexp import parse
 
 _MIN_JAVA_MAJOR = 21
 _REPO_ROOT = Path(__file__).resolve().parents[1]
@@ -60,7 +60,7 @@ def _java_major(java: str) -> int:
 def find_java() -> str | None:
     """Return a path to a Java >= 21 runtime, or None."""
     candidates: list[str] = []
-    override = os.environ.get("FREEROUTE_ORACLE_JAVA")
+    override = os.environ.get("RPMROUTE_ORACLE_JAVA") or os.environ.get("FREEROUTE_ORACLE_JAVA")
     if override:
         candidates.append(override)
     java_home = os.environ.get("JAVA_HOME")