Add screenshots, update metainfo, and fix AppImage build script

- Add 18 screenshots sorted by workflow order to data/screenshots/
- Update metainfo with actual screenshot entries and correct dimensions
- Fix build script to copy all hicolor icon sizes and use linuxdeploy --output
- Add exported icon PNGs to icons/

data/live.lashman.Pixstrip.metainfo.xml

@@ -51,44 +51,76 @@
 
   <screenshots>
     <screenshot type="default">
-      <caption>Workflow selection with built-in presets for common image tasks</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/01.png</image>
+      <caption>Workflow selection with built-in and user presets for common image tasks</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/01.png</image>
     </screenshot>
     <screenshot>
-      <caption>Image selection with drag-and-drop and batch file management</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/02.png</image>
+      <caption>Image selection with thumbnail grid and batch file management</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/02.png</image>
     </screenshot>
     <screenshot>
-      <caption>Resize step with width, height, fit-in-box, and social media presets</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/03.png</image>
+      <caption>Resize step with live preview, presets, and dimension controls</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/03.png</image>
     </screenshot>
     <screenshot>
-      <caption>Format conversion between JPEG, PNG, WebP, AVIF, GIF, and TIFF</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/04.png</image>
+      <caption>Format conversion with cards for JPEG, PNG, WebP, AVIF, GIF, TIFF, and BMP</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/04.png</image>
     </screenshot>
     <screenshot>
-      <caption>Compression with live before/after preview and file size estimates</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/05.png</image>
+      <caption>Compression with quality slider and live before/after preview</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/05.png</image>
     </screenshot>
     <screenshot>
-      <caption>Metadata stripping with selective EXIF field management</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/06.png</image>
+      <caption>Image adjustments for brightness, contrast, saturation, and effects</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/06.png</image>
     </screenshot>
     <screenshot>
-      <caption>Watermark placement with text and image options</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/07.png</image>
+      <caption>Metadata handling with preset modes and custom category toggles</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/07.png</image>
     </screenshot>
     <screenshot>
-      <caption>Batch rename with templates, counters, and EXIF variables</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/08.png</image>
+      <caption>Text watermark placement with live preview on image</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/08.png</image>
     </screenshot>
     <screenshot>
-      <caption>Image adjustments for brightness, contrast, and saturation</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/09.png</image>
+      <caption>Batch rename with prefix, suffix, case conversion, and live file preview</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/09.png</image>
     </screenshot>
     <screenshot>
-      <caption>Settings with output preferences and file manager integration</caption>
-      <image type="source" width="902" height="1330">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/10.png</image>
+      <caption>Output summary with operation checklist, directory, and overwrite settings</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/10.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Processing complete with results showing images processed and space saved</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/11.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Save workflow as a reusable preset with custom name, icon, and color</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/12.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Settings with output defaults, interface options, and file manager integration</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/13.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Processing history with recent batches and space savings</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/14.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Keyboard shortcuts for wizard navigation, file management, and more</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/15.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Welcome screen with quick introduction to Pixstrip</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/16.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Setup wizard to choose between simple and detailed interface modes</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/17.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>Contextual help with detailed guidance for each wizard step</caption>
+      <image type="source" width="1369" height="1081">https://git.lashman.live/lashman/pixstrip/raw/branch/main/data/screenshots/18.png</image>
     </screenshot>
   </screenshots>