docs: Add Gallery section to README with clickable thumbnails

Add HTML table with 150px thumbnail previews of all screenshots.
Images are clickable to view full size. Updated and added new
screenshots for menu, map, console, and image preview features.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -195,6 +195,42 @@ git checkout main
 
 ---
 
+## Gallery
+
+<table>
+  <tr>
+    <td align="center"><a href="gallery/main_window.png"><img src="gallery/main_window.png" width="150"><br>Main Window</a></td>
+    <td align="center"><a href="gallery/dm.png"><img src="gallery/dm.png" width="150"><br>Direct Messages</a></td>
+    <td align="center"><a href="gallery/unread_msgs.png"><img src="gallery/unread_msgs.png" width="150"><br>Unread Messages</a></td>
+    <td align="center"><a href="gallery/msg_archive.png"><img src="gallery/msg_archive.png" width="150"><br>Message Archive</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="gallery/menu_1.png"><img src="gallery/menu_1.png" width="150"><br>Menu (1)</a></td>
+    <td align="center"><a href="gallery/menu_2.png"><img src="gallery/menu_2.png" width="150"><br>Menu (2)</a></td>
+    <td align="center"><a href="gallery/device_info.png"><img src="gallery/device_info.png" width="150"><br>Device Info</a></td>
+    <td align="center"><a href="gallery/update_check.png"><img src="gallery/update_check.png" width="150"><br>Update Check</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="gallery/contact_management.png"><img src="gallery/contact_management.png" width="150"><br>Contact Management</a></td>
+    <td align="center"><a href="gallery/existing_contacts.png"><img src="gallery/existing_contacts.png" width="150"><br>Existing Contacts</a></td>
+    <td align="center"><a href="gallery/approve_contact.png"><img src="gallery/approve_contact.png" width="150"><br>Approve Contact</a></td>
+    <td align="center"><a href="gallery/channel_management.png"><img src="gallery/channel_management.png" width="150"><br>Channel Management</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="gallery/map.png"><img src="gallery/map.png" width="150"><br>Map</a></td>
+    <td align="center"><a href="gallery/map_individual.png"><img src="gallery/map_individual.png" width="150"><br>Map (Individual)</a></td>
+    <td align="center"><a href="gallery/image_preview_1.png"><img src="gallery/image_preview_1.png" width="150"><br>Image Preview (1)</a></td>
+    <td align="center"><a href="gallery/image_preview_2.png"><img src="gallery/image_preview_2.png" width="150"><br>Image Preview (2)</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="gallery/meshcli_console.png"><img src="gallery/meshcli_console.png" width="150"><br>Meshcli Console</a></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+</table>
+
+---
 
 ## Documentation