wip: dashboard wiring (real backend) + Docker compose for production

backend/.dockerignore

@@ -0,0 +1,24 @@
+# Exclude everything not needed at runtime from the backend image.
+# This file is read when backend/ is used as the build context. The
+# docker-compose build uses the repo root as context and references
+# `backend/...` paths explicitly, so most of these exclusions are belt-
+# and-suspenders for any future `docker build backend/` invocation.
+
+**/__pycache__
+**/*.pyc
+**/*.pyo
+**/.pytest_cache
+**/.mypy_cache
+**/.ruff_cache
+**/.coverage
+**/.tox
+**/.venv
+**/venv
+**/node_modules
+tests/
+docs/
+.coverage*
+htmlcov/
+*.egg-info/
+build/
+dist/