feat(settings): put a sync-now button on the four cards that lacked one

A route with no caller is an API detail, not a feature. The Oura, Polar,
Strava and Nightscout cards get the same action WHOOP already had, in the
same row as Test connection, rendered only once connected: post the sync,
show the count or the failure, invalidate the reads that depend on
measurements. No full-history dialog, since these providers have no such
arm. Keys added across the six locales.

messages/de.json

@@ -5543,6 +5543,9 @@
     "nightscoutUpdate": "Änderungen speichern",
     "nightscoutConnected": "Nightscout verbunden.",
     "nightscoutConnectFailed": "Verbindung zu Nightscout fehlgeschlagen.",
+    "nightscoutSync": "Jetzt synchronisieren",
+    "nightscoutSyncResult": "{count} Messwerte synchronisiert",
+    "nightscoutSyncFailed": "Synchronisierung fehlgeschlagen",
     "nightscoutDisconnect": "Trennen",
     "nightscoutDisconnectTitle": "Nightscout trennen?",
     "nightscoutDisconnectDescription": "Künftige Synchronisierungen stoppen. Bereits importierte Glukosewerte bleiben in deinem Verlauf.",
@@ -5558,6 +5561,9 @@
     "polarSaveCredentials": "Speichern",
     "polarUnavailable": "Polar ist auf diesem Server nicht konfiguriert. Füge oben deine eigenen Polar-OAuth-Zugangsdaten hinzu oder bitte deinen Administrator, die gemeinsame App zu konfigurieren.",
     "polarConnect": "Polar verbinden",
+    "polarSync": "Jetzt synchronisieren",
+    "polarSyncResult": "{count} Messwerte synchronisiert",
+    "polarSyncFailed": "Synchronisierung fehlgeschlagen",
     "polarDisconnect": "Trennen",
     "polarDisconnectTitle": "Polar trennen?",
     "polarDisconnectDescription": "Künftige Synchronisierungen stoppen. Bereits importierte Werte bleiben in deinem Verlauf.",
@@ -5585,6 +5591,9 @@
     "ouraSaveCredentials": "Speichern",
     "ouraUnavailable": "Oura ist auf diesem Server nicht konfiguriert. Füge oben deine eigenen Oura-OAuth-Zugangsdaten hinzu oder bitte deinen Administrator, die gemeinsame App zu konfigurieren.",
     "ouraConnect": "Oura verbinden",
+    "ouraSync": "Jetzt synchronisieren",
+    "ouraSyncResult": "{count} Messwerte synchronisiert",
+    "ouraSyncFailed": "Synchronisierung fehlgeschlagen",
     "ouraDisconnect": "Trennen",
     "ouraDisconnectTitle": "Oura trennen?",
     "ouraDisconnectDescription": "Künftige Synchronisierungen stoppen. Bereits importierte Werte bleiben in deinem Verlauf.",
@@ -5813,6 +5822,9 @@
     "stravaSaveCredentials": "Speichern",
     "stravaUnavailable": "Strava ist auf diesem Server nicht konfiguriert. Füge oben deine eigenen Strava-API-Zugangsdaten hinzu oder bitte deinen Administrator, die gemeinsame App zu konfigurieren.",
     "stravaConnect": "Strava verbinden",
+    "stravaSync": "Jetzt synchronisieren",
+    "stravaSyncResult": "{count} Messwerte synchronisiert",
+    "stravaSyncFailed": "Synchronisierung fehlgeschlagen",
     "stravaDisconnect": "Trennen",
     "stravaDisconnectTitle": "Strava trennen?",
     "stravaDisconnectDescription": "Künftige Synchronisierungen stoppen. Bereits importierte Aktivitäten bleiben in deinem Verlauf.",

messages/en.json

@@ -5533,6 +5533,9 @@
     "nightscoutUpdate": "Save changes",
     "nightscoutConnected": "Nightscout connected.",
     "nightscoutConnectFailed": "Could not connect to Nightscout.",
+    "nightscoutSync": "Sync now",
+    "nightscoutSyncResult": "{count} measurements synchronized",
+    "nightscoutSyncFailed": "Sync failed",
     "nightscoutDisconnect": "Disconnect",
     "nightscoutDisconnectTitle": "Disconnect Nightscout?",
     "nightscoutDisconnectDescription": "Future syncs stop. Glucose readings already imported stay in your history.",
@@ -5548,6 +5551,9 @@
     "polarSaveCredentials": "Save",
     "polarUnavailable": "Polar is not configured on this server. Add your own Polar OAuth credentials above, or ask your administrator to configure the shared app.",
     "polarConnect": "Connect Polar",
+    "polarSync": "Sync now",
+    "polarSyncResult": "{count} measurements synchronized",
+    "polarSyncFailed": "Sync failed",
     "polarDisconnect": "Disconnect",
     "polarDisconnectTitle": "Disconnect Polar?",
     "polarDisconnectDescription": "Future syncs stop. Readings already imported stay in your history.",
@@ -5575,6 +5581,9 @@
     "ouraSaveCredentials": "Save",
     "ouraUnavailable": "Oura is not configured on this server. Add your own Oura OAuth credentials above, or ask your administrator to configure the shared app.",
     "ouraConnect": "Connect Oura",
+    "ouraSync": "Sync now",
+    "ouraSyncResult": "{count} measurements synchronized",
+    "ouraSyncFailed": "Sync failed",
     "ouraDisconnect": "Disconnect",
     "ouraDisconnectTitle": "Disconnect Oura?",
     "ouraDisconnectDescription": "Future syncs stop. Readings already imported stay in your history.",
@@ -5803,6 +5812,9 @@
     "stravaSaveCredentials": "Save",
     "stravaUnavailable": "Strava is not configured on this server. Add your own Strava API credentials above, or ask your administrator to configure the shared app.",
     "stravaConnect": "Connect Strava",
+    "stravaSync": "Sync now",
+    "stravaSyncResult": "{count} measurements synchronized",
+    "stravaSyncFailed": "Sync failed",
     "stravaDisconnect": "Disconnect",
     "stravaDisconnectTitle": "Disconnect Strava?",
     "stravaDisconnectDescription": "Future syncs stop. Activities already imported stay in your history.",

messages/es.json

@@ -5545,6 +5545,9 @@
     "nightscoutUpdate": "Guardar cambios",
     "nightscoutConnected": "Nightscout conectado.",
     "nightscoutConnectFailed": "No se pudo conectar con Nightscout.",
+    "nightscoutSync": "Sincronizar ahora",
+    "nightscoutSyncResult": "{count} mediciones sincronizadas",
+    "nightscoutSyncFailed": "Error de sincronización",
     "nightscoutDisconnect": "Desconectar",
     "nightscoutDisconnectTitle": "¿Desconectar Nightscout?",
     "nightscoutDisconnectDescription": "Las sincronizaciones futuras se detienen. Las lecturas de glucosa ya importadas permanecen en tu historial.",
@@ -5560,6 +5563,9 @@
     "polarSaveCredentials": "Guardar",
     "polarUnavailable": "Polar no está configurado en este servidor. Añade arriba tus propias credenciales OAuth de Polar, o pide a tu administrador que configure la app compartida.",
     "polarConnect": "Conectar Polar",
+    "polarSync": "Sincronizar ahora",
+    "polarSyncResult": "{count} mediciones sincronizadas",
+    "polarSyncFailed": "Error de sincronización",
     "polarDisconnect": "Desconectar",
     "polarDisconnectTitle": "¿Desconectar Polar?",
     "polarDisconnectDescription": "Las sincronizaciones futuras se detienen. Las lecturas ya importadas permanecen en tu historial.",
@@ -5587,6 +5593,9 @@
     "ouraSaveCredentials": "Guardar",
     "ouraUnavailable": "Oura no está configurado en este servidor. Añade arriba tus propias credenciales OAuth de Oura, o pide a tu administrador que configure la app compartida.",
     "ouraConnect": "Conectar Oura",
+    "ouraSync": "Sincronizar ahora",
+    "ouraSyncResult": "{count} mediciones sincronizadas",
+    "ouraSyncFailed": "Error de sincronización",
     "ouraDisconnect": "Desconectar",
     "ouraDisconnectTitle": "¿Desconectar Oura?",
     "ouraDisconnectDescription": "Las sincronizaciones futuras se detienen. Las lecturas ya importadas permanecen en tu historial.",
@@ -5815,6 +5824,9 @@
     "stravaSaveCredentials": "Guardar",
     "stravaUnavailable": "Strava no está configurado en este servidor. Añade arriba tus propias credenciales de API de Strava o pide a tu administrador que configure la app compartida.",
     "stravaConnect": "Conectar Strava",
+    "stravaSync": "Sincronizar ahora",
+    "stravaSyncResult": "{count} mediciones sincronizadas",
+    "stravaSyncFailed": "Error de sincronización",
     "stravaDisconnect": "Desconectar",
     "stravaDisconnectTitle": "¿Desconectar Strava?",
     "stravaDisconnectDescription": "Las sincronizaciones futuras se detienen. Las actividades ya importadas permanecen en tu historial.",

messages/fr.json

@@ -5547,6 +5547,9 @@
     "nightscoutUpdate": "Enregistrer les modifications",
     "nightscoutConnected": "Nightscout connecté.",
     "nightscoutConnectFailed": "Impossible de se connecter à Nightscout.",
+    "nightscoutSync": "Synchroniser",
+    "nightscoutSyncResult": "{count} mesures synchronisées",
+    "nightscoutSyncFailed": "Échec de la synchronisation",
     "nightscoutDisconnect": "Déconnecter",
     "nightscoutDisconnectTitle": "Déconnecter Nightscout ?",
     "nightscoutDisconnectDescription": "Les synchronisations futures s'arrêtent. Les mesures de glycémie déjà importées restent dans votre historique.",
@@ -5562,6 +5565,9 @@
     "polarSaveCredentials": "Enregistrer",
     "polarUnavailable": "Polar n'est pas configuré sur ce serveur. Ajoutez vos propres identifiants OAuth Polar ci-dessus, ou demandez à votre administrateur de configurer l'application partagée.",
     "polarConnect": "Connecter Polar",
+    "polarSync": "Synchroniser",
+    "polarSyncResult": "{count} mesures synchronisées",
+    "polarSyncFailed": "Échec de la synchronisation",
     "polarDisconnect": "Déconnecter",
     "polarDisconnectTitle": "Déconnecter Polar ?",
     "polarDisconnectDescription": "Les synchronisations futures s'arrêtent. Les mesures déjà importées restent dans votre historique.",
@@ -5589,6 +5595,9 @@
     "ouraSaveCredentials": "Enregistrer",
     "ouraUnavailable": "Oura n'est pas configuré sur ce serveur. Ajoutez vos propres identifiants OAuth Oura ci-dessus, ou demandez à votre administrateur de configurer l'application partagée.",
     "ouraConnect": "Connecter Oura",
+    "ouraSync": "Synchroniser",
+    "ouraSyncResult": "{count} mesures synchronisées",
+    "ouraSyncFailed": "Échec de la synchronisation",
     "ouraDisconnect": "Déconnecter",
     "ouraDisconnectTitle": "Déconnecter Oura ?",
     "ouraDisconnectDescription": "Les synchronisations futures s'arrêtent. Les mesures déjà importées restent dans votre historique.",
@@ -5817,6 +5826,9 @@
     "stravaSaveCredentials": "Enregistrer",
     "stravaUnavailable": "Strava n'est pas configuré sur ce serveur. Ajoute tes propres identifiants API Strava ci-dessus ou demande à ton administrateur de configurer l'application partagée.",
     "stravaConnect": "Connecter Strava",
+    "stravaSync": "Synchroniser",
+    "stravaSyncResult": "{count} mesures synchronisées",
+    "stravaSyncFailed": "Échec de la synchronisation",
     "stravaDisconnect": "Déconnecter",
     "stravaDisconnectTitle": "Déconnecter Strava ?",
     "stravaDisconnectDescription": "Les synchronisations futures s'arrêtent. Les activités déjà importées restent dans ton historique.",

messages/it.json

@@ -5537,6 +5537,9 @@
     "nightscoutUpdate": "Salva modifiche",
     "nightscoutConnected": "Nightscout connesso.",
     "nightscoutConnectFailed": "Impossibile connettersi a Nightscout.",
+    "nightscoutSync": "Sincronizza ora",
+    "nightscoutSyncResult": "{count} misurazioni sincronizzate",
+    "nightscoutSyncFailed": "Sincronizzazione non riuscita",
     "nightscoutDisconnect": "Disconnetti",
     "nightscoutDisconnectTitle": "Disconnettere Nightscout?",
     "nightscoutDisconnectDescription": "Le sincronizzazioni future si interrompono. Le letture della glicemia già importate restano nella tua cronologia.",
@@ -5552,6 +5555,9 @@
     "polarSaveCredentials": "Salva",
     "polarUnavailable": "Polar non è configurato su questo server. Aggiungi sopra le tue credenziali OAuth di Polar oppure chiedi al tuo amministratore di configurare l'app condivisa.",
     "polarConnect": "Collega Polar",
+    "polarSync": "Sincronizza ora",
+    "polarSyncResult": "{count} misurazioni sincronizzate",
+    "polarSyncFailed": "Sincronizzazione non riuscita",
     "polarDisconnect": "Disconnetti",
     "polarDisconnectTitle": "Disconnettere Polar?",
     "polarDisconnectDescription": "Le sincronizzazioni future si interrompono. Le letture già importate restano nella tua cronologia.",
@@ -5579,6 +5585,9 @@
     "ouraSaveCredentials": "Salva",
     "ouraUnavailable": "Oura non è configurato su questo server. Aggiungi sopra le tue credenziali OAuth di Oura oppure chiedi al tuo amministratore di configurare l'app condivisa.",
     "ouraConnect": "Collega Oura",
+    "ouraSync": "Sincronizza ora",
+    "ouraSyncResult": "{count} misurazioni sincronizzate",
+    "ouraSyncFailed": "Sincronizzazione non riuscita",
     "ouraDisconnect": "Disconnetti",
     "ouraDisconnectTitle": "Disconnettere Oura?",
     "ouraDisconnectDescription": "Le sincronizzazioni future si interrompono. Le letture già importate restano nella tua cronologia.",
@@ -5807,6 +5816,9 @@
     "stravaSaveCredentials": "Salva",
     "stravaUnavailable": "Strava non è configurato su questo server. Aggiungi sopra le tue credenziali API di Strava o chiedi al tuo amministratore di configurare l'app condivisa.",
     "stravaConnect": "Collega Strava",
+    "stravaSync": "Sincronizza ora",
+    "stravaSyncResult": "{count} misurazioni sincronizzate",
+    "stravaSyncFailed": "Sincronizzazione non riuscita",
     "stravaDisconnect": "Disconnetti",
     "stravaDisconnectTitle": "Disconnettere Strava?",
     "stravaDisconnectDescription": "Le sincronizzazioni future si interrompono. Le attività già importate restano nella cronologia.",

messages/pl.json

@@ -5531,6 +5531,9 @@
     "nightscoutUpdate": "Zapisz zmiany",
     "nightscoutConnected": "Nightscout połączony.",
     "nightscoutConnectFailed": "Nie można połączyć z Nightscout.",
+    "nightscoutSync": "Synchronizuj teraz",
+    "nightscoutSyncResult": "Zsynchronizowano {count} pomiarów",
+    "nightscoutSyncFailed": "Synchronizacja nie powiodła się",
     "nightscoutDisconnect": "Rozłącz",
     "nightscoutDisconnectTitle": "Rozłączyć Nightscout?",
     "nightscoutDisconnectDescription": "Przyszłe synchronizacje zostaną zatrzymane. Już zaimportowane odczyty glukozy pozostaną w historii.",
@@ -5546,6 +5549,9 @@
     "polarSaveCredentials": "Zapisz",
     "polarUnavailable": "Polar nie jest skonfigurowany na tym serwerze. Dodaj powyżej własne dane OAuth Polar lub poproś administratora o skonfigurowanie współdzielonej aplikacji.",
     "polarConnect": "Połącz Polar",
+    "polarSync": "Synchronizuj teraz",
+    "polarSyncResult": "Zsynchronizowano {count} pomiarów",
+    "polarSyncFailed": "Synchronizacja nie powiodła się",
     "polarDisconnect": "Rozłącz",
     "polarDisconnectTitle": "Rozłączyć Polar?",
     "polarDisconnectDescription": "Przyszłe synchronizacje zostaną zatrzymane. Już zaimportowane odczyty pozostaną w historii.",
@@ -5573,6 +5579,9 @@
     "ouraSaveCredentials": "Zapisz",
     "ouraUnavailable": "Oura nie jest skonfigurowana na tym serwerze. Dodaj powyżej własne dane OAuth Oura lub poproś administratora o skonfigurowanie współdzielonej aplikacji.",
     "ouraConnect": "Połącz Oura",
+    "ouraSync": "Synchronizuj teraz",
+    "ouraSyncResult": "Zsynchronizowano {count} pomiarów",
+    "ouraSyncFailed": "Synchronizacja nie powiodła się",
     "ouraDisconnect": "Rozłącz",
     "ouraDisconnectTitle": "Rozłączyć Oura?",
     "ouraDisconnectDescription": "Przyszłe synchronizacje zostaną zatrzymane. Już zaimportowane odczyty pozostaną w historii.",
@@ -5801,6 +5810,9 @@
     "stravaSaveCredentials": "Zapisz",
     "stravaUnavailable": "Strava nie jest skonfigurowana na tym serwerze. Dodaj powyżej własne dane API Strava lub poproś administratora o skonfigurowanie wspólnej aplikacji.",
     "stravaConnect": "Połącz Strava",
+    "stravaSync": "Synchronizuj teraz",
+    "stravaSyncResult": "Zsynchronizowano {count} pomiarów",
+    "stravaSyncFailed": "Synchronizacja nie powiodła się",
     "stravaDisconnect": "Rozłącz",
     "stravaDisconnectTitle": "Rozłączyć Strava?",
     "stravaDisconnectDescription": "Przyszłe synchronizacje zostaną zatrzymane. Już zaimportowane aktywności pozostaną w historii.",

src/components/settings/integrations/__tests__/nightscout-card.test.tsx

@@ -83,3 +83,26 @@ describe("NightscoutCard — parked + test + data-link + invalidation", () => {
     expect(invalidatedKeys).toContainEqual(queryKeys.nightscoutStatus());
   });
 });
+
+/**
+ * v1.32.28 — sync now, matching the treatment the OAuth cards get.
+ */
+describe("NightscoutCard — sync-now action", () => {
+  it("offers the sync action on a connected instance", () => {
+    statusPayload = {
+      connected: true,
+      configured: true,
+      state: "connected",
+      lastSuccessAt: null,
+      lastError: null,
+    };
+    const html = render();
+    expect(html).toContain('data-testid="nightscout-sync"');
+    expect(html).toContain("Sync now");
+  });
+
+  it("does not offer it before an instance is configured", () => {
+    statusPayload = { connected: false, configured: false };
+    expect(render()).not.toContain('data-testid="nightscout-sync"');
+  });
+});

src/components/settings/integrations/__tests__/oauth-provider-card.test.tsx

@@ -178,3 +178,34 @@ describe("OAuthProviderCard — redirect-URI mini-guide (v1.29.x, UX audit H2)",
     expect(html).not.toContain('data-testid="polar-redirect-guide"');
   });
 });
+
+/**
+ * v1.32.28 — sync now. The route without the button would be an endpoint with
+ * no caller; the button is what makes the manual sync a feature rather than an
+ * API detail. Rendered only once the provider is connected, in the same action
+ * row as Test connection.
+ */
+describe("OAuthProviderCard — sync-now action", () => {
+  it("offers the sync action on a connected provider", () => {
+    statusPayload = {
+      connected: true,
+      configured: true,
+      available: true,
+      state: "connected",
+      lastSuccessAt: null,
+      lastError: null,
+    };
+    const html = render();
+    expect(html).toContain('data-testid="polar-sync"');
+    expect(html).toContain("Sync now");
+  });
+
+  it("does not offer it before the provider is connected", () => {
+    statusPayload = {
+      connected: false,
+      configured: true,
+      available: true,
+    };
+    expect(render()).not.toContain('data-testid="polar-sync"');
+  });
+});

src/components/settings/integrations/nightscout-card.tsx

@@ -15,6 +15,7 @@ import {
   Droplet,
   Link2,
   Loader2,
+  RefreshCw,
   Save,
   Unlink,
 } from "lucide-react";
@@ -96,6 +97,11 @@ export function NightscoutCard({ enabled = true }: { enabled?: boolean }) {
   const [saving, setSaving] = useState(false);
   const [msg, setMsg] = useState<string | null>(null);
   const [msgType, setMsgType] = useState<"success" | "error" | null>(null);
+  const [syncing, setSyncing] = useState(false);
+  const [syncMsg, setSyncMsg] = useState<string | null>(null);
+  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
 
   const { data: status } = useQuery({
     queryKey: queryKeys.nightscoutStatus(),
@@ -170,6 +176,39 @@ export function NightscoutCard({ enabled = true }: { enabled?: boolean }) {
     setSaving(false);
   }
 
+  // Sync now. Same shape as the WHOOP card's incremental arm, minus the
+  // full-history dialog — Nightscout has no full-sync arm to call.
+  async function handleSync() {
+    setSyncing(true);
+    setSyncMsg(null);
+    setSyncMsgType(null);
+    try {
+      const res = await apiFetchRaw("/api/nightscout/sync", { method: "POST" });
+      const json = await res.json();
+      if (res.ok) {
+        setSyncMsg(
+          t("settings.nightscoutSyncResult", { count: json.data.imported }),
+        );
+        setSyncMsgType("success");
+        void invalidateKeys(queryClient, measurementDependentKeys);
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.nightscoutStatus(),
+        });
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.integrationsStatus(),
+        });
+      } else {
+        setSyncMsg(json.error || t("settings.nightscoutSyncFailed"));
+        setSyncMsgType("error");
+      }
+    } catch {
+      setSyncMsg(t("settings.nightscoutSyncFailed"));
+      setSyncMsgType("error");
+    } finally {
+      setSyncing(false);
+    }
+  }
+
   const pillState = pillStateFor(status);
   const errorMessage =
     (pillState === "error" || pillState === "parked") && status?.lastError
@@ -337,6 +376,22 @@ export function NightscoutCard({ enabled = true }: { enabled?: boolean }) {
         {status?.connected && (
           <>
             <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
+              <Button
+                type="button"
+                variant="outline"
+                size="sm"
+                className="min-h-11"
+                onClick={handleSync}
+                disabled={syncing}
+                data-testid="nightscout-sync"
+              >
+                {syncing ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <RefreshCw className="h-3.5 w-3.5" />
+                )}
+                {t("settings.nightscoutSync")}
+              </Button>
               <TestConnectionButton
                 endpoint="/api/nightscout/test"
                 disabled={!status?.connected}
@@ -373,6 +428,15 @@ export function NightscoutCard({ enabled = true }: { enabled?: boolean }) {
                 </AlertDialogContent>
               </AlertDialog>
             </div>
+            {syncMsg && (
+              <p
+                role="alert"
+                data-testid="nightscout-sync-result"
+                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {syncMsg}
+              </p>
+            )}
             {/* connect→data loop: a discreet link to where the glucose
                 readings now surface — doubles as the "your data is richer"
                 cue. */}

src/components/settings/integrations/oauth-provider-card.tsx

@@ -15,6 +15,7 @@ import {
   ArrowRight,
   Link2,
   Loader2,
+  RefreshCw,
   Save,
   Unlink,
   type LucideIcon,
@@ -125,6 +126,11 @@ export function OAuthProviderCard({
   const { t } = useTranslations();
   const queryClient = useQueryClient();
   const [msg, setMsg] = useState<string | null>(null);
+  const [syncing, setSyncing] = useState(false);
+  const [syncMsg, setSyncMsg] = useState<string | null>(null);
+  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
   const [clientId, setClientId] = useState("");
   const [clientSecret, setClientSecret] = useState("");
   const [credsSaving, setCredsSaving] = useState(false);
@@ -145,6 +151,37 @@ export function OAuthProviderCard({
   });
   const status = viewModel ?? fetchedStatus;
 
+  // Sync now. Same shape as the WHOOP card's incremental arm, minus the
+  // full-history dialog — none of these providers has a full-sync arm to call.
+  async function handleSync() {
+    setSyncing(true);
+    setSyncMsg(null);
+    setSyncMsgType(null);
+    try {
+      const res = await apiFetchRaw(`/api/${provider}/sync`, {
+        method: "POST",
+      });
+      const json = await res.json();
+      if (res.ok) {
+        setSyncMsg(t(`${i18nPrefix}SyncResult`, { count: json.data.imported }));
+        setSyncMsgType("success");
+        void invalidateKeys(queryClient, measurementDependentKeys);
+        queryClient.invalidateQueries({ queryKey: statusQueryKey });
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.integrationsStatus(),
+        });
+      } else {
+        setSyncMsg(json.error || t(`${i18nPrefix}SyncFailed`));
+        setSyncMsgType("error");
+      }
+    } catch {
+      setSyncMsg(t(`${i18nPrefix}SyncFailed`));
+      setSyncMsgType("error");
+    } finally {
+      setSyncing(false);
+    }
+  }
+
   async function handleSaveCredentials(e: React.FormEvent) {
     e.preventDefault();
     setCredsSaving(true);
@@ -374,6 +411,22 @@ export function OAuthProviderCard({
         {status?.connected ? (
           <>
             <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
+              <Button
+                type="button"
+                variant="outline"
+                size="sm"
+                className="min-h-11"
+                onClick={handleSync}
+                disabled={syncing}
+                data-testid={`${provider}-sync`}
+              >
+                {syncing ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <RefreshCw className="h-3.5 w-3.5" />
+                )}
+                {t(`${i18nPrefix}Sync`)}
+              </Button>
               <TestConnectionButton
                 endpoint={`/api/${provider}/test`}
                 disabled={!status?.connected}
@@ -411,6 +464,15 @@ export function OAuthProviderCard({
                 </AlertDialogContent>
               </AlertDialog>
             </div>
+            {syncMsg && (
+              <p
+                role="alert"
+                data-testid={`${provider}-sync-result`}
+                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {syncMsg}
+              </p>
+            )}
             {/* connect→data loop: a discreet link to where this provider's
                 readings now surface — doubles as the "your data is richer"
                 cue. */}