Scaffold freeroute: Python port of the FreeRouting engine

Pure-Python PCB autorouter replacing the freerouting.jar step in kicad-mcp.
Contract is Specctra DSN in, SES out — a drop-in for the JAR so the toolchain
needs no JVM. Includes pyproject (uv/ruff/pytest, src-layout) and a porting
plan seeded for study of the upstream FreeRouting Java source.

src/freeroute/__init__.py

@@ -0,0 +1,3 @@
+"""freeroute — native Python PCB autorouter (Java-free FreeRouting port)."""
+
+__version__ = "0.1.0"