Add environment usage instructions

README.md

@@ -0,0 +1,28 @@
+This directory stores the packaged SpatialGT runtime environment for users who
+prefer not to rebuild the Python stack manually.
+
+Expected archive:
+
+```bash
+spatialgt_env.tar.gz
+```
+
+To restore it from the repository root:
+
+```bash
+mkdir -p environment
+tar -xzf environment/spatialgt_env.tar.gz -C environment
+```
+
+After extraction, the UI launcher will automatically find
+`environment/spatialgt/bin/python`:
+
+```bash
+bash spatialgt_agent_ui/run.sh
+```
+
+You can also point the launcher to any compatible environment:
+
+```bash
+bash spatialgt_agent_ui/run.sh --spatialgt /path/to/environment/spatialgt
+```