feat(deploy): add declarative installation workflow

tools/deployment/build-deployer-zipapp.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""Build the dependency-free GovOPlaN deployer as one executable zipapp."""
+
+from __future__ import annotations
+
+import argparse
+from hashlib import sha256
+from pathlib import Path
+import zipapp
+
+
+ROOT = Path(__file__).resolve().parent
+DEFAULT_OUTPUT = ROOT.parent.parent / "runtime" / "deployment" / "govoplan-deploy.pyz"
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--output", type=Path, default=DEFAULT_OUTPUT)
+    args = parser.parse_args(argv)
+
+    output = args.output.expanduser().resolve()
+    if output == ROOT or ROOT in output.parents:
+        raise SystemExit("output must be outside the deployment source directory")
+    output.parent.mkdir(mode=0o700, parents=True, exist_ok=True)
+    temporary = output.with_name(f".{output.name}.tmp")
+    if temporary.exists():
+        temporary.unlink()
+    zipapp.create_archive(
+        ROOT,
+        target=temporary,
+        interpreter="/usr/bin/env python3",
+        compressed=True,
+        filter=_include_source,
+    )
+    temporary.chmod(0o755)
+    temporary.replace(output)
+    digest = sha256(output.read_bytes()).hexdigest()
+    print(f"{digest}  {output}")
+    return 0
+
+
+def _include_source(path: Path) -> bool:
+    return (
+        "__pycache__" not in path.parts
+        and path.suffix not in {".pyc", ".pyo"}
+        and path.name != "build-deployer-zipapp.py"
+    )
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())