Add app icons across web, Android, and the desktop app

- Web: favicon.ico + png icons under static/, served from the site root
  and linked from every page head.
- Android: the artwork becomes the launcher icon — the 432px adaptive
  foreground over the gruvbox background, replacing the placeholder vector
  drawables.
- Desktop: the icon is the Qt window/taskbar icon (embedded via app.qrc),
  and the app is now an installable package — a wrapped binary, a
  photog.desktop entry, and hicolor icons — so `nix profile install
  ./desktop` puts "Photog" in the application menu.

desktop/CMakeLists.txt

@@ -4,6 +4,7 @@ project(photogallery_uploader LANGUAGES CXX)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
 
 find_package(Qt6 REQUIRED COMPONENTS Widgets Network Concurrent)
 find_package(Qt6Keychain REQUIRED)
@@ -15,6 +16,7 @@ add_executable(uploader
     settings.cpp
     uploadclient.cpp
     imageprep.cpp
+    app.qrc
 )
 
 target_link_libraries(uploader PRIVATE
@@ -23,3 +25,14 @@ target_link_libraries(uploader PRIVATE
     Qt6::Concurrent
     Qt6Keychain::Qt6Keychain
 )
+
+# Installation — the binary, a desktop entry, and the app icon in the hicolor
+# theme, so `nix profile install ./desktop` puts "Photog" in the app menu.
+include(GNUInstallDirs)
+install(TARGETS uploader RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+install(FILES photog.desktop DESTINATION ${CMAKE_INSTALL_DATADIR}/applications)
+foreach(sz 32 128 256 512)
+    install(FILES icons/app-${sz}.png
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/icons/hicolor/${sz}x${sz}/apps
+            RENAME photog.png)
+endforeach()

desktop/app.qrc

@@ -0,0 +1,9 @@
+<!DOCTYPE RCC>
+<RCC version="1.0">
+    <qresource prefix="/">
+        <file>icons/app-32.png</file>
+        <file>icons/app-128.png</file>
+        <file>icons/app-256.png</file>
+        <file>icons/app-512.png</file>
+    </qresource>
+</RCC>

desktop/flake.nix

@@ -17,6 +17,28 @@
           pkgs.qt6.qtimageformats
         ];
       in {
+        # Installable build: `nix profile install ./desktop` drops "Photog" into
+        # the application menu with its icon. wrapQtAppsHook wraps the binary so
+        # it finds the Qt platform (xcb + wayland) and image-format plugins on
+        # its own, without the dev shell.
+        packages.default = pkgs.stdenv.mkDerivation {
+          pname = "photog";
+          version = "0.1.0";
+          src = ./.;
+          nativeBuildInputs = with pkgs; [
+            cmake
+            ninja
+            pkg-config
+            qt6.wrapQtAppsHook
+          ];
+          buildInputs = with pkgs; [
+            qt6.qtbase
+            qt6.qtwayland
+            qt6.qtimageformats
+            qt6Packages.qtkeychain
+          ];
+        };
+
         devShells.default = pkgs.mkShell {
           packages = with pkgs; [
             cmake

desktop/main.cpp

@@ -1,4 +1,5 @@
 #include <QApplication>
+#include <QIcon>
 
 #include "mainwindow.h"
 
@@ -8,6 +9,15 @@ int main(int argc, char **argv)
     app.setApplicationName(QStringLiteral("photogallery-uploader"));
     app.setOrganizationName(QStringLiteral("inflo.ws"));
 
+    // Window / taskbar / alt-tab icon, embedded via app.qrc. Several sizes so
+    // the small titlebar rendering stays crisp rather than downscaling 512px.
+    QIcon icon;
+    icon.addFile(QStringLiteral(":/icons/app-32.png"));
+    icon.addFile(QStringLiteral(":/icons/app-128.png"));
+    icon.addFile(QStringLiteral(":/icons/app-256.png"));
+    icon.addFile(QStringLiteral(":/icons/app-512.png"));
+    app.setWindowIcon(icon);
+
     MainWindow window;
     window.resize(440, 680);
     window.show();

desktop/photog.desktop

@@ -0,0 +1,9 @@
+[Desktop Entry]
+Type=Application
+Name=Photog
+GenericName=Photo Uploader
+Comment=Upload photos to your gallery
+Exec=uploader
+Icon=photog
+Terminal=false
+Categories=Graphics;Photography;Network;