Initial public release — aci-sim v0.16.0

aci-sim is a stateful REST simulator of a 2-site Cisco ACI fabric
(per-site APIC + ND/NDO management planes) — for testing ACI automation
(Ansible cisco.aci / cisco.mso, aci-py, custom REST clients) and CI gates
without real hardware.

Highlights: APIC + NDO REST surface served from one in-memory MIT built
from a declarative topology.yaml; port mode + sandbox (real per-device IPs
on :443) run modes; LLDP/CDP neighbor visibility; NDO->APIC deploy mirror
(multi-site templates materialize onto the target sites' APIC stores);
real-APIC fvBD default attributes; file-backed state save/restore; an
`aci-sim` CLI (validate/show/graph/run/new/init/lldp); and an 888-test suite.

History squashed for the public release.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

aci_sim/mit/mo.py

@@ -0,0 +1,50 @@
+"""MO (Managed Object) — building block of the ACI Managed Information Tree."""
+
+from __future__ import annotations
+from typing import Any
+
+
+class MO:
+    """A single node in the ACI MIT.
+
+    Attributes
+    ----------
+    class_name : str          e.g. ``"fvTenant"``
+    attrs      : dict[str, str]   must include ``"dn"``
+    children   : list[MO]     direct children in this MO's subtree
+    """
+
+    def __init__(self, class_name: str, **attrs: str) -> None:
+        self.class_name = class_name
+        self.attrs: dict[str, str] = dict(attrs)
+        self.children: list[MO] = []
+
+    @property
+    def dn(self) -> str:
+        return self.attrs.get("dn", "")
+
+    def add_child(self, mo: MO) -> None:
+        """Append *mo* to this MO's children list."""
+        self.children.append(mo)
+
+    def flat(self) -> list[MO]:
+        """Return self + all descendants in depth-first order."""
+        result: list[MO] = [self]
+        for child in self.children:
+            result.extend(child.flat())
+        return result
+
+    def to_imdata(self) -> dict[str, Any]:
+        """Produce the APIC wire shape for this MO.
+
+        ``{"class_name": {"attributes": {...}, "children": [...]}}``
+
+        The ``children`` key is omitted when the MO has no children.
+        """
+        body: dict[str, Any] = {"attributes": dict(self.attrs)}
+        if self.children:
+            body["children"] = [c.to_imdata() for c in self.children]
+        return {self.class_name: body}
+
+    def __repr__(self) -> str:
+        return f"MO({self.class_name!r}, dn={self.dn!r})"