fix(node): a removal made at the machine is in audit.db

The Node page and the CLI remove access through the loopback API, and
revoke and unpin there wrote nothing to audit.db; only the signed MNP door
did. A removed person's next connection then showed an auth_failed with
nothing before it to explain it. Both routes now record member_revoke and
member_unpin once the operation has succeeded, with the node's own account
as the actor and 127.0.0.1 as the address, which tells the two doors apart.
A refusal changes nothing and records nothing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2 files changed, 61 insertions, 2 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/ui/app.py b/packages/meshbay-node/src/meshbay_node/ui/app.py
index f5cd5d0..9ed014b 100644
--- a/packages/meshbay-node/src/meshbay_node/ui/app.py
+++ b/packages/meshbay-node/src/meshbay_node/ui/app.py
@@ -371,15 +371,47 @@ def create_ui_app(state: dict) -> FastAPI:
         """Map a username to an account id, through the hub."""
         return await _op(lambda: ops.resolve_user(state, username))
 
+    async def _audit_local(event: str, subject: str, group_id: str = "") -> None:
+        """
+        Record a removal made at the machine (Node page or CLI) in audit.db.
+
+        The signed door over WebRTC records its own (`_audit` in the session);
+        this one has no session. The actor is the node's own account — whoever
+        holds the control API's token acts as it — and the address is the
+        loopback, which tells the two doors apart in the log.
+        """
+        audit = state.get("audit_store")
+        if not audit:
+            return
+        try:
+            await audit.log_event(
+                user_id=state.get("node_user_id") or "",
+                event=event,
+                ip="127.0.0.1",
+                username=getattr(getattr(state.get("config"), "hub", None), "username", "") or "",
+                group_id=group_id,
+                detail=subject,
+            )
+        except Exception as e:
+            log.warning("audit: could not record %s of %s: %s", event, subject[:8], e)
+
     @app.post("/api/members/{user_id}/revoke")
     async def revoke_member(user_id: str, group_id: str):
         """Stop serving the group key to a member."""
-        return await _op(lambda: ops.revoke_member(state, user_id, group_id))
+        async def run():
+            result = await ops.revoke_member(state, user_id, group_id)
+            await _audit_local("member_revoke", user_id, group_id)
+            return result
+        return await _op(run)
 
     @app.post("/api/members/{user_id}/unpin")
     async def unpin_member(user_id: str):
         """Forget a pinned identity, so the person can pair again with a new key."""
-        return await _op(lambda: ops.unpin_member(state, user_id))
+        async def run():
+            result = await ops.unpin_member(state, user_id)
+            await _audit_local("member_unpin", user_id)
+            return result
+        return await _op(run)
 
     # ── Chat encryption (operator only, localhost) ─────────────────────────
 
diff --git a/packages/meshbay-node/tests/test_roster_pairing.py b/packages/meshbay-node/tests/test_roster_pairing.py
index b2799e9..e2180ba 100644
--- a/packages/meshbay-node/tests/test_roster_pairing.py
+++ b/packages/meshbay-node/tests/test_roster_pairing.py
@@ -845,6 +845,33 @@ async def test_unpin_endpoint_allows_repairing(tmp_path, roster):
     assert client.post("/api/members/bob/unpin?t=tok").status_code == 404
 
 
+async def test_a_removal_at_the_machine_is_in_the_audit_log(tmp_path, roster):
+    """The Node page and the CLI remove through here; the signed WebRTC door
+    already wrote its own row, this one wrote none."""
+    from meshbay_node.audit import AuditStore
+
+    audit = AuditStore(db_path=tmp_path / "audit.db")
+    await audit.open()
+    try:
+        client, _ = _ui_client(tmp_path, roster, audit_store=audit)
+        _, pk_ed_b64, pk_x_b64 = _keypair()
+        await roster.pin_identity("bob", "bob", pk_ed_b64, pk_x_b64, "code")
+        await roster.set_member(GROUP, "bob", ROLE_MEMBER, "active", "grenet")
+
+        assert client.post(f"/api/members/bob/revoke?group_id={GROUP}&t=tok").status_code == 200
+        assert client.post("/api/members/bob/unpin?t=tok").status_code == 200
+        # A refusal changed nothing, so it records nothing.
+        assert client.post("/api/members/bob/unpin?t=tok").status_code == 404
+
+        rows = sorted(await audit.get_entries(), key=lambda e: e.id)
+        assert [(e.event, e.user_id, e.ip, e.group_id, e.detail) for e in rows] == [
+            ("member_revoke", "grenet", "127.0.0.1", GROUP, "bob"),
+            ("member_unpin", "grenet", "127.0.0.1", "", "bob"),
+        ]
+    finally:
+        await audit.close()
+
+
 async def test_operator_surface_needs_the_session_token(tmp_path, roster):
     """11.5.3 applies to every one of these: they change who may hold the key."""
     client, _ = _ui_client(tmp_path, roster)