Mobile UI pass: responsive tables, deck-view drill-down, dialog fixes

- Library/Card Search/Deck tables stack into dense card-style rows below
  720px instead of scrolling horizontally (floated thumbnail, wrapping
  chips for MV/Owned/color pips).
- Deck view: fix desktop min-widths and a non-wrapping button row that
  forced horizontal scroll on phones; split the deck list and the
  deck-building pane into separate drill-down screens with a back button
  so a long deck list doesn't bury the builder.
- Suggested Cards modal: fix action buttons crushing the card name down to
  one word per line by giving them their own full-width row.
- Add a close (X) button to the shared dialog title bar — mobile has no
  Escape key and wide dialogs leave little backdrop to tap.
- Info tab, bottom-nav loading/safe-area fixes, and Gradle NDK_HOME
  inheritance fix carried over from the Android bring-up work.

index.html

@@ -2,7 +2,11 @@
 <html lang="en">
   <head>
     <meta charset="UTF-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <!-- viewport-fit=cover: required for env(safe-area-inset-*) to report real
+         values rather than 0. The Android window already draws edge-to-edge
+         behind the status/nav bars (that's why content was overlapping them);
+         this is what lets CSS react to it instead of ignoring it. -->
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover" />
     <title>mtgc</title>
   </head>
   <body>