Add app icon, product name/version, and document them

- New app.ico (from the Cevolani favicon, background made transparent and
  cropped tighter to the logo so it stays legible at 16/24px), wired up via
  ApplicationIcon in the csproj and re-read at runtime for the window icon.
- Named the product "Cevolani StepPrep" and set Version=0.1.0 in the csproj;
  shown in the window title. The CadSearchGui folder/namespace/csproj keep
  their technical name, only the product-facing name changed.
- Updated CLAUDE.md, README.md and docs/architettura.md to reflect the
  product name/version, UiStile.cs, app.ico, and that this app is a
  pre-process step ahead of Creo Distributed Batch.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CadSearchGui/CadSearchGui.csproj

@@ -7,6 +7,11 @@
     <UseWindowsForms>true</UseWindowsForms>
     <ImplicitUsings>enable</ImplicitUsings>
     <ApplicationHighDpiMode>PerMonitorV2</ApplicationHighDpiMode>
+    <ApplicationIcon>app.ico</ApplicationIcon>
+    <AssemblyTitle>Cevolani StepPrep</AssemblyTitle>
+    <Product>Cevolani StepPrep</Product>
+    <Company>Cevolani</Company>
+    <Version>0.1.0</Version>
   </PropertyGroup>
 
   <ItemGroup>

CadSearchGui/Form1.cs

@@ -75,9 +75,21 @@ public partial class Form1 : Form
     private void BuildUi()
     {
         AllowDrop = true;
-        Text = "Distinta Base -> CSV con percorsi CAD";
+        // Versione letta dall'assembly (<Version> nel csproj) invece che duplicata qui a mano.
+        var versione = typeof(Form1).Assembly.GetName().Version;
+        Text = $"Cevolani StepPrep {versione?.ToString(3)} — Distinta Base -> CSV con percorsi CAD";
         MinimumSize = new Size(760, 480);
         Font = new Font("Segoe UI", 9.5f);
+        // Stessa icona di ApplicationIcon nel csproj: la si rilegge dall'exe compilato invece
+        // di duplicare il file .ico come Content, funziona identica in Debug/Release/publish.
+        try
+        {
+            Icon = Icon.ExtractAssociatedIcon(Application.ExecutablePath);
+        }
+        catch (Exception ex) when (ex is IOException or ArgumentException)
+        {
+            // ponytail: nessuna icona nell'exe (es. lanciato da dotnet run) -> resta quella di default
+        }
 
         var headerPanel = new Panel { Dock = DockStyle.Top, Height = 40, BackColor = SystemColors.ControlLight };
         _lblFase.Dock = DockStyle.Fill;