feat: RDG qwinsta/logoff via WinRM on client workstation (0.11.6)

SAC resolves internal_ip to a registered Windows host and runs qwinsta/logoff synchronously over WinRM instead of queueing commands to the gateway agent.

backend/app/services/rdg_client_host.py

@@ -0,0 +1,50 @@
+"""Resolve RDG client workstation (session host) from event internal_ip."""
+
+from __future__ import annotations
+
+from sqlalchemy import or_, select
+from sqlalchemy.orm import Session
+
+from app.models import Event, Host
+from app.services.rdg_session_flap import event_internal_ip
+from app.services.winrm_connect import is_windows_host
+
+
+class ClientWorkstationNotFoundError(Exception):
+    def __init__(self, internal_ip: str) -> None:
+        self.internal_ip = internal_ip
+        super().__init__(
+            f"Client workstation not found in SAC hosts for internal_ip={internal_ip}. "
+            "Ensure the PC is registered with matching ipv4."
+        )
+
+
+def find_windows_host_by_ipv4(db: Session, ipv4: str) -> Host | None:
+    ip = (ipv4 or "").strip()
+    if not ip:
+        return None
+    rows = db.scalars(
+        select(Host)
+        .where(
+            Host.ipv4 == ip,
+            or_(
+                Host.os_family.ilike("windows"),
+                Host.product == "rdp-login-monitor",
+            ),
+        )
+        .order_by(Host.last_seen_at.desc())
+    ).all()
+    for host in rows:
+        if is_windows_host(host):
+            return host
+    return None
+
+
+def resolve_client_workstation(db: Session, event: Event) -> Host:
+    internal_ip = event_internal_ip(event)
+    if not internal_ip:
+        raise ClientWorkstationNotFoundError("")
+    host = find_windows_host_by_ipv4(db, internal_ip)
+    if host is None:
+        raise ClientWorkstationNotFoundError(internal_ip)
+    return host