feat(ops): VersionWatcher — toast prompt when a new deploy is live

Client-side polling component mounted in providers.tsx. At mount,
captures the initial commit from /api/version. Every 60s, re-checks.
If commit differs from the captured one → renders a dismissible toast
in the bottom-right offering a hard reload.

Useful because Next.js bundles cache per commit hash → after a deploy
users would otherwise keep running the old client until they manually
refresh. Now they get a discoverable nudge.

Banner UX:
- "Versiune nouă disponibilă: <shortSha> · apasă pentru reîncărcare"
- [Reîncarcă] button (window.location.reload)
- [X] dismiss for current page life
- Tailwind animate-in fade slide-from-bottom

Polling interval 60s is fine for our deploy frequency; cheap (one
GET per minute, ~150 bytes). Cache-busted with cache: "no-store".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/providers.tsx

@@ -5,6 +5,7 @@ import { I18nProvider } from '@/core/i18n';
 import { StorageProvider } from '@/core/storage';
 import { FeatureFlagProvider } from '@/core/feature-flags';
 import { AuthProvider } from '@/core/auth';
+import { VersionWatcher } from '@/core/version/version-watcher';
 import { DEFAULT_FLAGS } from '@/config/flags';
 
 // Ensure module registry is populated
@@ -22,6 +23,7 @@ export function Providers({ children }: ProvidersProps) {
           <FeatureFlagProvider flagDefinitions={DEFAULT_FLAGS}>
             <AuthProvider>
               {children}
+              <VersionWatcher />
             </AuthProvider>
           </FeatureFlagProvider>
         </StorageProvider>

src/core/version/version-watcher.tsx

@@ -0,0 +1,76 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+import { RefreshCw, X } from "lucide-react";
+
+const POLL_INTERVAL_MS = 60_000;
+const ENDPOINT = "/api/version";
+
+type VersionPayload = { commit: string; commitShort: string; buildTime: string };
+
+export function VersionWatcher() {
+  const initialRef = useRef<string | null>(null);
+  const [latest, setLatest] = useState<VersionPayload | null>(null);
+  const [dismissed, setDismissed] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+
+    const fetchVersion = async () => {
+      try {
+        const res = await fetch(ENDPOINT, { cache: "no-store" });
+        if (!res.ok || cancelled) return;
+        const data = (await res.json()) as VersionPayload;
+        if (!data?.commit) return;
+        if (initialRef.current === null) {
+          initialRef.current = data.commit;
+          return;
+        }
+        if (data.commit !== initialRef.current) {
+          setLatest(data);
+        }
+      } catch {
+        // network noise — ignore
+      }
+    };
+
+    fetchVersion();
+    const interval = setInterval(fetchVersion, POLL_INTERVAL_MS);
+    return () => {
+      cancelled = true;
+      clearInterval(interval);
+    };
+  }, []);
+
+  if (!latest || dismissed) return null;
+
+  return (
+    <div
+      role="status"
+      className="fixed bottom-4 right-4 z-[60] flex items-center gap-2 rounded-lg border bg-background/95 px-3 py-2 shadow-lg backdrop-blur animate-in fade-in slide-in-from-bottom-2"
+    >
+      <RefreshCw className="h-4 w-4 text-primary" />
+      <div className="flex flex-col text-xs">
+        <span className="font-medium">Versiune nouă disponibilă</span>
+        <span className="text-muted-foreground">
+          <code className="font-mono">{latest.commitShort}</code> · apasă pentru reîncărcare
+        </span>
+      </div>
+      <button
+        type="button"
+        onClick={() => window.location.reload()}
+        className="ml-2 rounded bg-primary px-2 py-1 text-xs font-medium text-primary-foreground hover:bg-primary/90"
+      >
+        Reîncarcă
+      </button>
+      <button
+        type="button"
+        onClick={() => setDismissed(true)}
+        className="rounded p-1 text-muted-foreground hover:bg-muted hover:text-foreground"
+        aria-label="Închide"
+      >
+        <X className="h-3.5 w-3.5" />
+      </button>
+    </div>
+  );
+}