Webapp redesign phase 2: Overview and imaging floor

Imaging floor (/imaging, /imaging/tiles):
- One line per PC: status chip, serial with machine number, hostname
  and IP, stage text with a segmented stage track, one action plus a
  '...' menu. Everything else (description, error, timestamps, Intune
  ID + QR, Set category / ARTS links, LAPS QR, log tail) is in the row's
  expandable body.
- Order: failed, needs action (stage 7), in progress, done; log-only
  bays fold into one collapsed group. imaging_status.floor_state() and
  floor_order() compute this.
- Status filter buttons with live counts next to the text filter. SSE
  refresh, expanded-row memory and LAPS handling are unchanged.
- Stage text is never truncated; BIOS updates and erasing are bold.

Overview (/):
- Services popover, technician to-do line, the six most urgent floor
  rows (?limit=6 partial, refreshed every 15 s), and image cards with
  lint warnings, map errors and missing zips as separate chips. New,
  clone, delete and unattend stay on the cards' menus.

Copy buttons are now handled once in static/app.js, with a fallback for
plain-http pages where navigator.clipboard is unavailable.

webapp/static/app.js

@@ -467,3 +467,30 @@ document.addEventListener('DOMContentLoaded', function () {
 
 });
 
+
+// Copy buttons: any .copy-btn[data-copy-text], on every page. The LAN is
+// plain http, so navigator.clipboard is often unavailable; fall back to a
+// hidden textarea + execCommand. The button briefly reads "Copied".
+document.addEventListener('click', function (e) {
+    var btn = e.target.closest && e.target.closest('.copy-btn');
+    if (!btn) return;
+    var text = btn.getAttribute('data-copy-text') || '';
+    if (!text) return;
+    var done = function (ok) {
+        var orig = btn.getAttribute('data-orig-label') || btn.textContent;
+        btn.setAttribute('data-orig-label', orig);
+        btn.textContent = ok ? 'Copied' : 'Copy failed';
+        setTimeout(function () { btn.textContent = orig; }, 1400);
+    };
+    if (navigator.clipboard && window.isSecureContext) {
+        navigator.clipboard.writeText(text).then(function () { done(true); }, function () { done(false); });
+        return;
+    }
+    var ta = document.createElement('textarea');
+    ta.value = text; ta.setAttribute('readonly', ''); ta.style.position = 'fixed'; ta.style.opacity = '0';
+    document.body.appendChild(ta); ta.select();
+    var ok = false;
+    try { ok = document.execCommand('copy'); } catch (err) { ok = false; }
+    document.body.removeChild(ta);
+    done(ok);
+});