feat: per-host WinRM/SSH credentials override (0.5.17)

Allow host-level login/password for home/workgroup PCs while keeping global domain admins in Settings.

backend/app/services/host_remote_actions.py

@@ -14,7 +14,7 @@ from app.database import SessionLocal
 from app.models import Host
 from app.services.agent_update import execute_agent_update_fallback
 from app.services.agent_update_types import AgentUpdateFallbackResult
-from app.services.linux_admin_settings import get_effective_linux_admin_config
+from app.services.linux_admin_settings import get_effective_linux_admin_for_host
 from app.services.agent_update_settings import get_effective_agent_update_config
 from app.services.ssh_connect import (
     iter_ssh_targets,
@@ -97,7 +97,7 @@ def _completion_message(result: SshCommandResult) -> str:
 
 
 def _fetch_ssh_update_log_tail(db: Session, host: Host, *, lines: int = 200) -> str:
-    cfg = get_effective_linux_admin_config(db)
+    cfg = get_effective_linux_admin_for_host(db, host)
     if not cfg.configured:
         return ""
     try:
@@ -191,7 +191,7 @@ def _poll_ssh_update_log_loop(
             payload = dict(row.remote_action or {})
             if (payload.get("status") or "").strip().lower() != "running":
                 continue
-            cfg = get_effective_linux_admin_config(session)
+            cfg = get_effective_linux_admin_for_host(session, row)
             if not cfg.configured:
                 continue
             try:
@@ -322,7 +322,7 @@ def start_host_remote_action(
 
 
 def run_ssh_monitor_update_action(db: Session, host: Host) -> SshCommandResult:
-    cfg = get_effective_linux_admin_config(db)
+    cfg = get_effective_linux_admin_for_host(db, host)
     if not cfg.configured:
         return SshCommandResult(
             ok=False,