fix(installer): improve ISCC diagnostics and icon handling

- make SetupIconFile optional in Inno script

- print full ISCC stdout/stderr on build failure

- copy icon.ico into dist artifacts explicitly

installer/AnabasisManager.iss

@@ -28,7 +28,9 @@ SolidCompression=yes
 WizardStyle=modern
 ArchitecturesInstallIn64BitMode=x64compatible
 UninstallDisplayIcon={app}\AnabasisManager.exe
+#ifexist MyIconFile
 SetupIconFile={#MyIconFile}
+#endif
 
 [Languages]
 Name: "russian"; MessagesFile: "compiler:Languages\Russian.isl"