Fix monitor selection: resolve /f and /monitors: parameter conflict

Root cause: /f (fullscreen) parameter conflicts with /monitors: in FreeRDP 2.11.5
causing specific monitor selection to fall back to single monitor display.

Changes:
- Reorder command generation to check monitor config before resolution
- Skip /f when using specific monitor selection (/monitors:1,2 or /monitors:1,2,0)
- Keep /f only for 'All Monitors' and single monitor scenarios
- Add test script to validate new command generation logic

This should fix the issue where:
- 'All Monitors' works correctly (uses /f + /multimon)
- '2 Monitors' and '3 Monitors' were showing only 1 monitor

Expected result: /monitors:1,2 without /f should now properly display on 2 monitors

rdp_client.py

@@ -842,10 +842,17 @@ Multi-Monitor Support:
                 if conn.get("domain"):
                     cmd.append(f"/d:{conn['domain']}")
                 
-                # Resolution
+                # Check monitor configuration first to determine resolution handling
+                multimon = conn.get("multimon", "No")
+                use_specific_monitors = multimon in ["2 Monitors", "3 Monitors", "4 Monitors"]
+                
+                # Resolution - avoid /f with specific monitor selection due to conflicts
                 resolution = conn.get("resolution", "1920x1080")
-                if resolution == "Full Screen":
+                if resolution == "Full Screen" and not use_specific_monitors:
                     cmd.append("/f")
+                elif resolution == "Full Screen" and use_specific_monitors:
+                    # Don't use /f with specific monitors - let /monitors: determine the layout
+                    self.logger.info("Skipping /f (fullscreen) due to specific monitor selection")
                 else:
                     cmd.append(f"/size:{resolution}")
                 
@@ -853,11 +860,9 @@ Multi-Monitor Support:
                 color_depth = conn.get("color_depth", 32)
                 cmd.append(f"/bpp:{color_depth}")
                 
-                # Multiple monitors
-                multimon = conn.get("multimon", "No")
+                # Multiple monitors - use /monitors: without /multimon for specific selection
                 if multimon == "2 Monitors":
                     monitor_list = self._get_best_monitor_selection(2)
-                    # Try using /monitors without /multimon for specific monitor selection
                     cmd.append(f"/monitors:{monitor_list}")
                     self.logger.info(f"Using specific monitors for 2 monitors: {monitor_list}")
                 elif multimon == "3 Monitors":