feat: Implement recipe selection with backend integration

Backend changes (C#):
- Add SelectRecipe method to MachineBridge for recipe selection
- Add currentRecipeId tracking in MainForm
- Implement SELECT_RECIPE handler in WebSocketServer

Frontend changes (React/TypeScript):
- Add selectRecipe method to communication layer
- Update handleSelectRecipe to call backend and handle response
- Recipe selection updates ModelInfoPanel automatically
- Add error handling and logging for recipe operations

Layout improvements:
- Add Layout component with persistent Header and Footer
- Create separate IOMonitorPage for full-screen I/O monitoring
- Add dynamic IO tab switcher in Header (Inputs/Outputs)
- Ensure consistent UI across all pages

🤖 Generated with Claude Code

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

backend/HMIWeb/MainForm.cs

@@ -25,6 +25,7 @@ namespace HMIWeb
         private bool[] inputs = new bool[32];
         private bool[] outputs = new bool[32];
         private string systemState = "IDLE";
+        private string currentRecipeId = "1"; // Default recipe
         public MainForm()
         {
             InitializeComponent();
@@ -77,7 +78,7 @@ namespace HMIWeb
             webView.CoreWebView2.AddHostObjectToScript("machine", new MachineBridge(this));
 
             // 3. Load UI
-            //webView.Source = new Uri("http://hmi.local/index.html");
+            webView.Source = new Uri("http://hmi.local/index.html");
 
             // Disable default browser keys (F5, F12 etc) if needed for kiosk mode
             webView.CoreWebView2.Settings.AreDefaultContextMenusEnabled = false;
@@ -153,6 +154,18 @@ namespace HMIWeb
             systemState = (cmd == "START") ? "RUNNING" : (cmd == "STOP") ? "PAUSED" : "IDLE";
         }
 
+        public void SetCurrentRecipe(string recipeId)
+        {
+            currentRecipeId = recipeId;
+            Console.WriteLine($"[MainForm] Current recipe set to: {recipeId}");
+            // In real app, load recipe parameters here
+        }
+
+        public string GetCurrentRecipe()
+        {
+            return currentRecipeId;
+        }
+
         private double Lerp(double a, double b, double t) => a + (b - a) * t;
     }
 }