fix(apps): balance column count so 4-on-3-col wraps to 2x2 instead of leaving an orphan card

Screenshot showed a 4-card category laying out as 3+1 (three cards on
row 1, Wireguard Easy alone on row 2 with two card-shaped empty cells
on its right). Fixed-width tracks + auto-fill kept the cards aligned
across categories but couldn't avoid the orphan — pure CSS grid has
no way to collapse partial-row trailing cells when the column above
them is filled.

apps-manager.js now picks --app-cols deliberately: the natural
column count for the viewport, reduced by one when the last row
would otherwise be exactly one orphan card. 4 cards on a 3-col
viewport becomes 2x2; 5 cards stays at 3+2; 6 stays at 3+3+0; 7
drops to 2-col so the last row gets a partner (still has one orphan
at the very end since 7 is prime, but never below 2 cols — a single
column stack reads worse than an orphan).

CSS swap: grid-template-columns now consumes the new --app-cols
custom property and uses minmax(--app-min, 1fr) so cards stretch
within their tracks (the orphan-prevention dance means widths can
vary across categories now — tradeoff for never having internal
gaps). 1-card view still shrinks the box via the existing formula
so a lone card isn't stretched across the full row.

Signed-off-by: librelad <librelad@digitalangels.vip>

containers/libreportal/frontend/css/apps.css

@@ -6,25 +6,25 @@
   --app-min: 300px;
   --app-gap: 20px;
   display: grid;
-  /* Fixed-width tracks (not minmax/1fr) so cards stay exactly --app-min
+  /* JS sets --app-cols to a balanced track count: as many as fit the
-     wide regardless of how many are visible — a 2-card category lines up
+     row at min-width, but reduced by 1 if the natural count would
-     with a 3-card category at the same X positions. 1fr stretching used
+     orphan a single card on the last row (e.g. 4 cards on a 3-col
-     to rubber-band card widths between categories as the box width
+     viewport becomes a 2x2 grid instead of 3+1). Falls back to
-     changed. */
+     auto-fill while JS hasn't run yet. Cards stretch via 1fr so the
-  grid-template-columns: repeat(auto-fill, var(--app-min));
+     last row never leaves a card-shaped hole — accepting some width
+     variation across categories in exchange for no internal gaps. */
+  grid-template-columns: repeat(var(--app-cols, auto-fill), minmax(var(--app-min), 1fr));
   gap: var(--app-gap);
   margin: 22px;
   padding: 22px;
   background: rgba(var(--text-rgb), 0.025);
   border: 1px solid var(--border-subtle);
   border-radius: 16px;
-  /* Shrink the glass box to exactly the visible-card count so a row with
+  /* Box reaches the layout edge for 2+ visible cards (sentinel from
-     two apps doesn't leave a card-shaped hole on the right. --app-count
+     apps-manager.js); for a single card the formula caps the box to
-     is set from apps-manager.js (render + search filter); the 100%-44px
+     one card's worth instead of stretching it across the full row.
-     cap keeps the same 22px gutter when the formula would otherwise
+     Outer under border-box (global, style.css:4): N*min + (N-1)*gap +
-     exceed parent width. Outer width under border-box (global default,
+     44px padding + 2px border + 2px sub-pixel buffer. */
-     style.css:4): N*min + (N-1)*gap + 44px padding + 2px border + 2px
-     buffer for sub-pixel rounding. Default 99 = no cap until JS reports. */
   max-width: min(
     calc(100% - 44px),
     calc(var(--app-count, 99) * var(--app-min) + (var(--app-count, 99) - 1) * var(--app-gap) + 48px)

containers/libreportal/frontend/js/components/app/apps-manager.js

@@ -552,17 +552,21 @@ class AppsManager {
     });
   }
 
-  // Sync --app-count on .apps-section. The CSS formula shrinks the glass
+  // Sync --app-cols + --app-count on .apps-section so the grid lays out
-  // box around the visible cards when there are too few to fill a row
+  // without orphans on the last row.
-  // (so 1-2 cards on a 3-col viewport don't leave a card-shaped hole).
+  //
-  // When the visible count already meets the natural full-width column
+  // --app-cols picks a balanced column count: as many as the row fits
-  // count, we pass a large sentinel (99) so the formula overshoots the
+  // naturally, but reduced by 1 when the natural choice would leave a
-  // 100%-44px parent cap and the box reaches the layout edge — otherwise
+  // single card alone on the last row (e.g. 4 cards on a 3-col viewport
-  // a row with "exactly enough" cards would leave a visible gap between
+  // becomes 2x2 instead of 3+1). 5+2, 6+3, etc are accepted — only the
-  // the box's right edge and the parent. Cards themselves are fixed
+  // worst case (last row has exactly 1 orphan) is rebalanced.
-  // --app-min width via the grid template, so widths line up across
+  //
-  // categories regardless of which branch fires. Driven from render,
+  // --app-count drives the CSS max-width cap: 1 visible card shrinks
-  // sidebar search filter, and window resize.
+  // the box to one card's worth (stretching one card to 1000px+ looks
+  // bad); 2+ cards pass a sentinel (99) so the cap defers to the
+  // 100%-44px parent and the box runs edge-to-edge.
+  //
+  // Driven from render, sidebar search filter, and window resize.
   updateAppsCount() {
     const container = document.getElementById('apps-section');
     if (!container) return;
@@ -579,11 +583,22 @@ class AppsManager {
     // 22px margin + 22px padding + 1px border, doubled.
     const parent = container.parentElement;
     const inside = parent ? Math.max(0, parent.clientWidth - 90) : 0;
-    const naturalCols = inside > 0
+    const maxCols = inside > 0
       ? Math.max(1, Math.floor((inside + gap) / (minCol + gap)))
       : visible;
-    const effective = visible >= naturalCols ? 99 : visible;
+
-    container.style.setProperty('--app-count', effective);
+    let cols = Math.min(visible, maxCols);
+    // Avoid orphaning a single card on the last row — reduce columns
+    // by one so the layout becomes (cols-1)+(cols-1)+… with a fuller
+    // tail. Don't drop below 2; a 1-col stack looks worse than an
+    // orphan. Only handles the immediate "last row is 1" case;
+    // last-row-of-2 etc are accepted as good enough.
+    if (cols > 2 && visible > cols && visible % cols === 1) {
+      cols--;
+    }
+
+    container.style.setProperty('--app-cols', cols);
+    container.style.setProperty('--app-count', visible === 1 ? 1 : 99);
   }
 
   // Client-side substring filter wired to the sidebar search box.