chore: remove uv-init leftover stub main.py

Untouched `uv init` placeholder (print("Hello from instamesh-docker!")). Not
imported, not wired as an entry point, and documented in this repo's
own README/CLAUDE.md as leftover scaffolding not on the build path.

main.py

@@ -1,6 +0,0 @@
-def main():
-    print("Hello from instamesh-docker!")
-
-
-if __name__ == "__main__":
-    main()