Server web UI: stop text selection from firing during photo-card drags

A press-and-drag gesture over a card's badge/button text also triggered
the browser's native selection highlight, distracting and occasionally
fighting the pointer-based drag tracking closely enough to break it.

server/app/templates/base.html

@@ -249,6 +249,12 @@
          which switches this to "none" for the rest of that touch --
          only once we're sure it's a deliberate drag, not a scroll. */
       touch-action: pan-y;
+      /* Without this, a press-and-drag gesture also triggers the
+         browser's native text/content selection (the blue highlight) --
+         distracting, and on some browsers it fights the pointer-based
+         drag tracking below closely enough to break it outright. */
+      user-select: none;
+      -webkit-user-select: none;
     }
     .photo-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-1px); }
     .photo-card:active { cursor: grabbing; }