Add release versioning and Docker release workflow

app/version.py

@@ -0,0 +1,10 @@
+from pathlib import Path
+
+VERSION_FILE = Path(__file__).resolve().parent.parent / "VERSION"
+
+
+def read_version() -> str:
+    return VERSION_FILE.read_text(encoding="utf-8").strip()
+
+
+__version__ = read_version()