fix(web): Started toggle survives the Executions card's 5s poll

The card's own htmx poll re-renders the whole table from the server every
5s, always starting fresh at "relative" -- so a toggled-to-absolute cell
snapped back on the next poll. Each button now has a stable id
(started-{run_id}-{attempt}, or started-vm-{vmx} on an unmatched-VM row);
app.js remembers which format was showing per id and re-applies it to the
fresh button after every swap, rather than freezing the node itself (which
would also freeze its relative-time text, badge, duration, everything else
in that row).

src/ci_orchestrator/web/static/app.js

@@ -197,27 +197,56 @@
     }).observe(stack, { childList: true });
   }
 
-  document.body.addEventListener("htmx:afterSwap", function (evt) {
-    var target = evt.detail && evt.detail.target;
-    if (target && target.id === "action-slot") {
-      processSlot(target);
-    }
-  });
-
   // Executions "Started" cell: click swaps between the relative and
   // absolute time already rendered into the button's own data attributes --
   // no request. Delegated on body (not the button itself) so it keeps
   // working after the Executions card's own 5s htmx poll replaces the row.
+  //
+  // The poll re-renders the whole card from the server every 5s, always
+  // starting back at "relative" -- so the choice is remembered here, keyed
+  // by the button's own id (stable across polls: run id/attempt or vmx),
+  // and re-applied to the fresh button restoreTimeToggles() finds after each
+  // swap, rather than freezing the node itself (which would also freeze its
+  // relative-time text, badge, duration -- everything else in the row).
+  var timeToggleState = {};
+
+  function applyTimeToggle(btn, showing) {
+    var shown = showing === "relative" ? "absolute" : "relative";
+    btn.textContent = btn.dataset[showing];
+    btn.title = btn.dataset[shown];
+    btn.dataset.showing = showing;
+  }
+
+  function restoreTimeToggles(root) {
+    var buttons = root.querySelectorAll ? root.querySelectorAll(".time-toggle[id]") : [];
+    Array.prototype.forEach.call(buttons, function (btn) {
+      var saved = timeToggleState[btn.id];
+      if (saved && saved !== btn.dataset.showing) {
+        applyTimeToggle(btn, saved);
+      }
+    });
+  }
+
   document.body.addEventListener("click", function (evt) {
     var btn = evt.target.closest(".time-toggle");
     if (!btn) {
       return;
     }
     var next = btn.dataset.showing === "relative" ? "absolute" : "relative";
-    var shown = next === "relative" ? "absolute" : "relative";
-    btn.textContent = btn.dataset[next];
-    btn.title = btn.dataset[shown];
-    btn.dataset.showing = next;
+    applyTimeToggle(btn, next);
+    if (btn.id) {
+      timeToggleState[btn.id] = next;
+    }
+  });
+
+  document.body.addEventListener("htmx:afterSwap", function (evt) {
+    var target = evt.detail && evt.detail.target;
+    if (target && target.id === "action-slot") {
+      processSlot(target);
+    }
+    if (target) {
+      restoreTimeToggles(target);
+    }
   });
 
   document.addEventListener("DOMContentLoaded", function () {