feat: add neutral, notes, and quiet alternate app icons

Low-profile icon variants for the disguise/opsec path in #1447. Asset
catalogs are picked up via ASSETCATALOG_COMPILER_INCLUDE_ALL_APPICON_ASSETS.

bitchat/Assets.xcassets/AppIconNeutral.appiconset/Contents.json

@@ -0,0 +1,74 @@
+{
+  "images": [
+    {
+      "filename": "icon_1024x1024.png",
+      "idiom": "universal",
+      "platform": "ios",
+      "size": "1024x1024"
+    },
+    {
+      "filename": "icon_16x16.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "16x16"
+    },
+    {
+      "filename": "icon_16x16@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "16x16"
+    },
+    {
+      "filename": "icon_32x32.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "32x32"
+    },
+    {
+      "filename": "icon_32x32@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "32x32"
+    },
+    {
+      "filename": "icon_128x128.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "128x128"
+    },
+    {
+      "filename": "icon_128x128@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "128x128"
+    },
+    {
+      "filename": "icon_256x256.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "256x256"
+    },
+    {
+      "filename": "icon_256x256@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "256x256"
+    },
+    {
+      "filename": "icon_512x512.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "512x512"
+    },
+    {
+      "filename": "icon_512x512@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "512x512"
+    }
+  ],
+  "info": {
+    "author": "xcode",
+    "version": 1
+  }
+}

bitchat/Assets.xcassets/AppIconNotes.appiconset/Contents.json

@@ -0,0 +1,74 @@
+{
+  "images": [
+    {
+      "filename": "icon_1024x1024.png",
+      "idiom": "universal",
+      "platform": "ios",
+      "size": "1024x1024"
+    },
+    {
+      "filename": "icon_16x16.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "16x16"
+    },
+    {
+      "filename": "icon_16x16@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "16x16"
+    },
+    {
+      "filename": "icon_32x32.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "32x32"
+    },
+    {
+      "filename": "icon_32x32@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "32x32"
+    },
+    {
+      "filename": "icon_128x128.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "128x128"
+    },
+    {
+      "filename": "icon_128x128@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "128x128"
+    },
+    {
+      "filename": "icon_256x256.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "256x256"
+    },
+    {
+      "filename": "icon_256x256@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "256x256"
+    },
+    {
+      "filename": "icon_512x512.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "512x512"
+    },
+    {
+      "filename": "icon_512x512@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "512x512"
+    }
+  ],
+  "info": {
+    "author": "xcode",
+    "version": 1
+  }
+}

bitchat/Assets.xcassets/AppIconQuiet.appiconset/Contents.json

@@ -0,0 +1,74 @@
+{
+  "images": [
+    {
+      "filename": "icon_1024x1024.png",
+      "idiom": "universal",
+      "platform": "ios",
+      "size": "1024x1024"
+    },
+    {
+      "filename": "icon_16x16.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "16x16"
+    },
+    {
+      "filename": "icon_16x16@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "16x16"
+    },
+    {
+      "filename": "icon_32x32.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "32x32"
+    },
+    {
+      "filename": "icon_32x32@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "32x32"
+    },
+    {
+      "filename": "icon_128x128.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "128x128"
+    },
+    {
+      "filename": "icon_128x128@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "128x128"
+    },
+    {
+      "filename": "icon_256x256.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "256x256"
+    },
+    {
+      "filename": "icon_256x256@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "256x256"
+    },
+    {
+      "filename": "icon_512x512.png",
+      "idiom": "mac",
+      "scale": "1x",
+      "size": "512x512"
+    },
+    {
+      "filename": "icon_512x512@2x.png",
+      "idiom": "mac",
+      "scale": "2x",
+      "size": "512x512"
+    }
+  ],
+  "info": {
+    "author": "xcode",
+    "version": 1
+  }
+}