tx-os(#344): polish UpcomingMeetingAlert per user feedback

Four UI changes requested by an Arabic-speaking user on the floating
"اجتماع يبدأ قريباً" popup:

1. Time window LTR — wrap the header `alert-time-window` span in
   `dir="ltr"` so the start time always appears on the left and the
   end on the right, even inside the Arabic RTL UI. Prevents the
   "م 3:20 – م 3:10" reversal seen in the user's screenshot.
2. Drop the duplicate "Time" row inside DetailsPanel — the same
   start/end window is already shown in the header strip. Removed
   the `if (timeWindow) rows.push({ key: "time", ... })` block; the
   `timeWindow` local was deleted along with it. Header is now the
   single source of truth.
3. Remove the labelled "تجاهل التنبيه" footer button. The X close
   button in the header still calls `handleDismiss`, so users can
   still dismiss; the action bar is now just Done / Postpone /
   Details. `handleDismiss`, `dismissToast`, and the i18n keys are
   left intact for the X button.
4. Make the "يبدأ خلال N دقائق" / "يبدأ الآن" countdown blink red.
   Added a dedicated `@keyframes em-blink` (1s, opacity 1 → 0.15 →
   1) and `.em-blink` class in `src/index.css`, with a
   `prefers-reduced-motion` override that pins it at full opacity.
   Countdown span uses `text-red-600 em-blink font-semibold`. The
   previously-used `accentText` local had no remaining consumers,
   so it was removed (replaced with an explanatory comment).

Files:
- artifacts/tx-os/src/components/executive-meetings/upcoming-meeting-alert.tsx
- artifacts/tx-os/src/index.css

Verification: `pnpm -C artifacts/tx-os exec tsc --noEmit` clean.
Architect review APPROVED (PASS). No tests referenced the removed
`alert-dismiss` / `alert-details-time` testids.

Pre-existing failures (unrelated): api-server workflow and the
combined `test` workflow continue to fail with the same upstream
issues observed in #342/#343 trajectory; this change does not
touch the API server or e2e test infrastructure.

artifacts/tx-os/src/components/executive-meetings/upcoming-meeting-alert.tsx

@@ -481,7 +481,8 @@ export function UpcomingMeetingAlert() {
   const dividerColor = hexToRgba(alertPrefs.accent, 0.45);
   const closeHoverBg = hexToRgba(alertPrefs.accent, 0.25);
   const detailsBg = hexToRgba(alertPrefs.accent, 0.12);
-  const accentText = alertPrefs.accent;
+  // #344: `accentText` was removed because the only consumer (the
+  // "starts in N minutes" headline) now uses a fixed red blink class.
 
   return (
     <>
@@ -561,8 +562,7 @@ export function UpcomingMeetingAlert() {
           </div>
           <div className="mt-1 flex flex-wrap items-center gap-x-3 gap-y-1 text-xs">
             <span
-              className="font-semibold"
-              style={{ color: accentText }}
+              className="em-blink font-semibold text-red-600"
               data-testid="alert-countdown"
             >
               {headline}
@@ -571,6 +571,12 @@ export function UpcomingMeetingAlert() {
               <span
                 className="inline-flex items-center gap-1 opacity-80"
                 data-testid="alert-time-window"
+                // The time window is always rendered LTR (start on the
+                // left, end on the right) even inside the Arabic UI —
+                // requested explicitly by the user (#344). The clock
+                // icon precedes the digits in source order; with
+                // dir="ltr" that puts it visually on the left.
+                dir="ltr"
               >
                 <Clock className="h-3 w-3" aria-hidden="true" />
                 {meeting.endTime
@@ -623,16 +629,13 @@ export function UpcomingMeetingAlert() {
               {t("executiveMeetings.alert.postpone")}
             </Button>
           ) : null}
-          <Button
-            type="button"
-            size="sm"
-            variant="outline"
-            onClick={handleDismiss}
-            disabled={savingAction !== null}
-            data-testid="alert-dismiss"
-          >
-            {t("executiveMeetings.alert.dismiss")}
-          </Button>
+          {/*
+            #344: The labelled "Dismiss alert" button was removed at
+            the user's request — the X close button in the header
+            (which still calls handleDismiss) is the single way to
+            hide the popup, keeping the action bar focused on
+            "Done" / "Postpone" / "Details".
+          */}
           <Button
             type="button"
             size="sm"
@@ -1771,13 +1774,10 @@ function DetailsPanel({
     }
   })();
 
-  // #307: Pre-compute the rendered time-window string so the row is
-  // skipped entirely when the meeting has no scheduled times.
-  const timeWindow = meeting.startTime
-    ? meeting.endTime
-      ? `${formatTime(meeting.startTime, lang)} – ${formatTime(meeting.endTime, lang)}`
-      : formatTime(meeting.startTime, lang)
-    : null;
+  // #344: The "time" row in the details panel duplicated the time
+  // window already shown in the header strip, so it was removed at
+  // the user's request. Header is the single source of truth for the
+  // start/end times.
 
   // Each row renders a label cell + a value cell inside the parent
   // CSS grid. Skipping rows whose value is missing keeps the table
@@ -1791,15 +1791,6 @@ function DetailsPanel({
   };
   const rows: Row[] = [];
 
-  if (timeWindow) {
-    rows.push({
-      key: "time",
-      icon: <Clock className="h-3.5 w-3.5 opacity-70" aria-hidden="true" />,
-      label: t("executiveMeetings.alert.detailsTime"),
-      value: <span data-testid="alert-details-time">{timeWindow}</span>,
-    });
-  }
-
   if (meeting.location && meeting.location.trim()) {
     rows.push({
       key: "location",

artifacts/tx-os/src/index.css

@@ -339,3 +339,21 @@
   }
 }
 
+/*
+ * #344: Attention-grabbing blink for the "starts in N minutes" headline
+ * inside the floating UpcomingMeetingAlert. Tailwind's `animate-pulse`
+ * only fades to opacity 0.5, which doesn't read as a true blink, so we
+ * ship a dedicated keyframe that drops to 0.15 and back. Respects the
+ * user's reduced-motion preference by stopping at full opacity.
+ */
+@keyframes em-blink {
+  0%, 100% { opacity: 1; }
+  50%      { opacity: 0.15; }
+}
+.em-blink {
+  animation: em-blink 1s ease-in-out infinite;
+}
+@media (prefers-reduced-motion: reduce) {
+  .em-blink { animation: none; opacity: 1; }
+}
+