fix(multi): resolve 3 remaining Android UI bugs

- radial_menu: replace active_id.unwrap() with let Some guard — no
  runtime panic possible even if DragState races (§2.3)
- card_plugin: add bottom-right AndroidCornerBg overlay to mask the
  rotated baked-in text on classic PNG cards (mirrors top-left treatment)
- hud_plugin: bump Android action button min_width 44→52 px to give
  ~22px glyphs adequate padding after dynamic font-size increase
- layout: fix doc-lazy-continuation clippy lint in BOTTOM_BAR_HEIGHT comment

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_engine/src/hud_plugin.rs

@@ -989,7 +989,7 @@ fn spawn_action_button<M: Component>(
     // centred with room to breathe. On desktop, keep the comfortable 48 dp
     // floor and 8 dp side padding.
     #[cfg(target_os = "android")]
-    let (pad, min_w, min_h) = (UiRect::axes(Val::Px(4.0), Val::Px(4.0)), Val::Px(44.0), Val::Px(44.0));
+    let (pad, min_w, min_h) = (UiRect::axes(Val::Px(4.0), Val::Px(4.0)), Val::Px(52.0), Val::Px(44.0));
     #[cfg(not(target_os = "android"))]
     let (pad, min_w, min_h) = (UiRect::axes(VAL_SPACE_2, VAL_SPACE_2), Val::Px(48.0), Val::Px(48.0));