fix(onboarding): identity read that survives a rewrite, disk refused before the pull — 0.1.8

Three faults from one agent-managed onboarding (env-dev-08, 2026-09-09), each of which pointed
the diagnosis away from the actual fault.

1. install.sh granted the agent's read on the ziti identity with a POSIX ACL. ziti-edge-tunnel
   rewrites that file on a controller config update and the rewrite drops the ACL: the agent
   applied cleanly at 01:21 and was failing every tick by 01:32. Group membership survives the
   rewrite (the file stays ziti:ziti 0640), so install.sh and the package postinstall now add
   monky-deployd to the `ziti` group, and a default ACL on the identity directory carries the
   grant onto a newly created file. The explicit ACLs stay for the boxes that need them.

2. openziti.load() accepts an unreadable or malformed identity: the C SDK logs "configuration is
   invalid" and returns a context that only fails at dial, as a bare TypeError, which the
   transport reported as a missing intercept or a policy gap. The SDK transport now reads and
   parses the identity itself and names the real fault first.

3. The disk pre-flight ran only when the bundle declared disk_need_bytes, so a bundle without one
   died mid-pull with containerd's "no space left on device" — which reads as a registry fault.
   A bundle that declares no size now has to clear the headroom floor, and the pre-flight measures
   containerd's root as well as the docker data-root: docker 29 keeps image layers in the
   containerd image store, and on env-dev-08 those sat on different filesystems (93 GiB free where
   the agent looked, 2.8 GiB where the pull wrote).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KLB7jieMNRkTsJ2epr4Ds1

tests/test_agent.py

@@ -237,6 +237,30 @@ def test_disk_refusal(bootstrapped, tenancy, fake_docker):
     assert tenancy.leases == []
 
 
+def test_disk_refusal_without_a_declared_size(bootstrapped, tenancy, fake_docker, monkeypatch):
+    """A bundle that declares no size still has to clear the headroom floor.
+
+    Without the floor a nearly-full box passes the pre-flight and dies mid-pull with
+    containerd's "no space left on device", which reads as a registry fault (env-dev-08).
+    """
+    cfg = bootstrapped
+    cfg.disk.headroom_bytes = 2 * 1024**3
+    monkeypatch.setattr("monky_deployd.compose.Docker.free_bytes", lambda self, path=None: 32 * 2**20)
+    tenancy.set_files(make_files())
+    assert tick(cfg) == EX_FAIL
+    detail = tenancy.reports[-1]["detail"]
+    assert "DISK_INSUFFICIENT" in detail and "declares no size" in detail
+    assert tenancy.leases == []
+
+
+def test_ample_disk_without_a_declared_size_applies(bootstrapped, tenancy, fake_docker, monkeypatch):
+    cfg = bootstrapped
+    monkeypatch.setattr("monky_deployd.compose.Docker.free_bytes", lambda self, path=None: 500 * 2**30)
+    tenancy.set_files(make_files())
+    assert tick(cfg) == EX_OK
+    assert tenancy.reports[-1]["result"] == "applied"
+
+
 def test_legacy_approle_lease_is_refused_loudly(bootstrapped, tenancy, fake_docker):
     cfg = bootstrapped
     tenancy.lease_shape = "approle"