feat: new skeuomorphic tabbed-terminal app icon (#47)

* feat: new skeuomorphic tabbed-terminal app icon

Replace the cmux chevron mark with a Programa-branded icon: a dark terminal
window with a tab strip (traffic lights + active/inactive tabs) and a glowing
blue->purple prompt chevron and cursor. Authored as a full-bleed 1024 layer in
the Tahoe AppIcon.icon (Icon Composer applies the platform shape, glass and
shadow), and regenerated the AppIcon-Debug.appiconset PNGs to match.

* fix: point AppIcon.icon at programa-terminal + refresh debug appiconset

Completes the icon swap: update icon.json to reference programa-terminal.png
(the prior commit removed the old chevron asset) and regenerate the
AppIcon-Debug.appiconset PNGs to the new design.

Author: arzafran

AppIcon.icon/Assets/cmux-icon-chevron 2.png

@@ -5,13 +5,13 @@
       "layers" : [
         {
           "glass" : false,
-          "image-name" : "cmux-icon-chevron 2.png",
-          "name" : "cmux-icon-chevron 2",
+          "image-name" : "programa-terminal.png",
+          "name" : "programa-terminal",
           "position" : {
             "scale" : 1,
             "translation-in-points" : [
-              37.357790031201375,
-              -0.5
+              0,
+              0
             ]
           }
         }
@@ -21,8 +21,8 @@
         "opacity" : 0.5
       },
       "translucency" : {
-        "enabled" : true,
-        "value" : 0.5
+        "enabled" : false,
+        "value" : 0
       }
     }
   ],