feat: multi-type server support — SQL, Redis, Grafana, Prometheus, Telnet, WinRM, RDP/VNC

Full implementation of multi-type server management across GUI and CLI:

New clients: SQLClient (MariaDB/MSSQL/PostgreSQL), RedisClient, GrafanaClient,
PrometheusClient, TelnetSession, WinRMClient, RemoteDesktopLauncher.

New GUI tabs: QueryTab (SQL editor + Treeview), RedisTab (console + history),
GrafanaTab (dashboards + alerts), PrometheusTab (PromQL + targets),
PowershellTab (PS/CMD), LaunchTab (RDP/VNC external client).

Infrastructure: TAB_REGISTRY for conditional tabs per server type,
adaptive server_dialog fields, colored type badges in sidebar,
status checker for all types (SSH/TCP/SQL/Redis/HTTP), 100+ i18n keys.

CLI: ssh.py extended with --sql, --redis, --grafana-*, --prom-*, --ps, --cmd.

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

core/connection_factory.py

@@ -1,7 +1,6 @@
 """
-Connection factory — stubs for non-SSH connection types.
-SSH is fully implemented via SSHClientWrapper.
-Other types are placeholders for future implementation.
+Connection factory — creates connection wrappers based on server type.
+Uses lazy imports so missing optional dependencies don't crash the app.
 """
 
 from core.ssh_client import SSHClientWrapper
@@ -14,12 +13,32 @@ def create_connection(server: dict, key_path: str = ""):
     if server_type == "ssh":
         return SSHClientWrapper(server, key_path)
 
-    # Stubs for future types
-    if server_type == "rdp":
-        raise NotImplementedError("RDP connections — use mstsc.exe or rdesktop")
     if server_type == "telnet":
-        raise NotImplementedError("Telnet connections — planned")
+        from core.telnet_client import TelnetSession
+        return TelnetSession(server)
+
     if server_type in ("mariadb", "mssql", "postgresql"):
-        raise NotImplementedError(f"{server_type.upper()} connections — planned")
+        from core.sql_client import SQLClient
+        return SQLClient(server)
+
+    if server_type == "redis":
+        from core.redis_client import RedisClient
+        return RedisClient(server)
+
+    if server_type == "grafana":
+        from core.grafana_client import GrafanaClient
+        return GrafanaClient(server)
+
+    if server_type == "prometheus":
+        from core.prometheus_client import PrometheusClient
+        return PrometheusClient(server)
+
+    if server_type == "winrm":
+        from core.winrm_client import WinRMClient
+        return WinRMClient(server)
+
+    if server_type in ("rdp", "vnc"):
+        from core.remote_desktop import RemoteDesktopLauncher
+        return RemoteDesktopLauncher()
 
     raise ValueError(f"Unknown server type: {server_type}")