feat: delegate project register; registrar-only ID minting

STATE-WP-0080-T02: statehub register routes project-flavor scaffolding
through rmgr scaffold and keeps only repo + host-path registration.
T01 refuse remains when GOAL.md is missing and --wp-prefix is not set.

RMGR-WP-0005-T01: C-06/C-11/C-32 skip mint+writeback unless this
instance is the identifier registrar (STATEHUB_REGISTRAR or railiance
hostname).

tests/test_statehub_register_cli.py

@@ -12,6 +12,7 @@ from custodian_cli import cmd_fix_consistency
 from statehub_register import (
     RegisterInference,
     detect_project_flavor_signal,
+    project_registration_plan,
     refuse_project_flavor_scaffold,
     run_register,
     _invoke_llm,
@@ -205,6 +206,132 @@ def test_run_register_refuses_prj_repo_without_writing_or_calling_api(
     assert not (repo / "workplans").exists()
 
 
+def test_project_registration_plan_durable_vs_refuse_vs_delegate(tmp_path: Path):
+    durable = tmp_path / "demo-service"
+    durable.mkdir()
+    assert project_registration_plan(durable) == ("durable", None)
+
+    fresh = tmp_path / "prj-example"
+    fresh.mkdir()
+    assert project_registration_plan(fresh)[0] == "refuse"
+    assert project_registration_plan(fresh, wp_prefix="EXCO-WP") == (
+        "delegate",
+        "EXCO-WP",
+    )
+
+    (fresh / "GOAL.md").write_text(
+        "---\nrepo_flavor: project\n---\n# Goal\n", encoding="utf-8"
+    )
+    assert project_registration_plan(fresh) == ("register-only", None)
+    assert project_registration_plan(fresh, wp_prefix="EXCO-WP") == (
+        "register-only",
+        None,
+    )
+
+
+def _stub_register_io(monkeypatch: pytest.MonkeyPatch):
+    written: list[dict] = []
+    registered: list[tuple] = []
+
+    monkeypatch.setattr("statehub_register._check_api", lambda *_a, **_k: None)
+    monkeypatch.setattr(
+        "statehub_register._api_get",
+        lambda path, *_a, **_k: (
+            [{"slug": "infotech", "id": "dom-1"}]
+            if str(path).startswith("/domains")
+            else [{"id": "topic-1", "slug": "infotech", "domain_slug": "infotech"}]
+        ),
+    )
+    monkeypatch.setattr(
+        "statehub_register.write_registration_files",
+        lambda **kwargs: written.append(kwargs) or [],
+    )
+    monkeypatch.setattr(
+        "statehub_register._register_or_update_repo",
+        lambda **kwargs: registered.append(("repo", kwargs)) or {"id": "repo-1"},
+    )
+    monkeypatch.setattr(
+        "statehub_register._register_host_path",
+        lambda *a, **k: registered.append(("path", a, k)),
+    )
+    monkeypatch.setattr("statehub_register._record_progress", lambda *_a, **_k: None)
+    return written, registered
+
+
+def _register_args(path: Path, **overrides):
+    values = {
+        "path": str(path),
+        "repo_slug": None,
+        "wp_prefix": None,
+        "domain": "infotech",
+        "description": "Test project.",
+        "intent": None,
+        "api_base": "http://unused",
+        "no_llm": True,
+        "force": False,
+        "llm_provider": "mock",
+        "llm_model": None,
+        "llm_api_key": None,
+        "llm_timeout": 5,
+    }
+    values.update(overrides)
+    return argparse.Namespace(**values)
+
+
+def test_run_register_delegates_project_scaffold_and_skips_templating(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+):
+    repo = tmp_path / "prj-example"
+    repo.mkdir()
+    written, registered = _stub_register_io(monkeypatch)
+    delegated: list[dict] = []
+
+    def fake_delegate(project_path, **kwargs):
+        delegated.append(kwargs)
+        (project_path / "GOAL.md").write_text(
+            "---\nrepo_flavor: project\n---\n# Goal\n", encoding="utf-8"
+        )
+        return {"status": "applied"}
+
+    monkeypatch.setattr("statehub_register.delegate_project_scaffold", fake_delegate)
+
+    run_register(_register_args(repo, wp_prefix="EXCO-WP"))
+
+    assert delegated == [
+        {
+            "slug": "prj-example",
+            "wp_prefix": "EXCO-WP",
+            "domain": "infotech",
+            "force": False,
+        }
+    ]
+    assert written == []
+    assert [kind for kind, *_ in registered] == ["repo", "path"]
+    assert not (repo / "INTENT.md").exists()
+    assert (repo / "GOAL.md").is_file()
+
+
+def test_run_register_existing_project_skips_scaffold_and_templating(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+):
+    repo = tmp_path / "prj-example"
+    repo.mkdir()
+    (repo / "GOAL.md").write_text(
+        "---\nrepo_flavor: project\n---\n# Goal\n", encoding="utf-8"
+    )
+    written, registered = _stub_register_io(monkeypatch)
+    monkeypatch.setattr(
+        "statehub_register.delegate_project_scaffold",
+        lambda *_a, **_k: (_ for _ in ()).throw(AssertionError("should not scaffold")),
+    )
+
+    run_register(_register_args(repo))
+
+    assert written == []
+    assert [kind for kind, *_ in registered] == ["repo", "path"]
+    assert not (repo / "INTENT.md").exists()
+
+
 def test_write_registration_files_is_idempotent_without_force(tmp_path: Path):
     inference = RegisterInference()
     kwargs = {