v1.9.40: Grafana basic auth support (user/password + api_token)

- Add user/password fields to Grafana in server dialog FIELD_MAP
- GrafanaClient: support basic auth when no api_token is set
- ssh.py: _grafana_request supports basic auth fallback

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gui/server_dialog.py

@@ -20,7 +20,7 @@ FIELD_MAP = {
     "mssql":      ["user", "password", "database"],
     "postgresql":  ["user", "password", "database"],
     "redis":      ["password", "db_index", "use_ssl"],
-    "grafana":    ["api_token", "use_ssl"],
+    "grafana":    ["user", "password", "api_token", "use_ssl"],
     "prometheus": ["use_ssl"],
     "rdp":        ["user", "password", "rdp_resolution", "rdp_quality", "rdp_clipboard", "rdp_drives", "rdp_printers"],
     "vnc":        ["password"],