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.

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"');
+  });
+});