fix: keep play_arrow spinning instead of switching to sync/progress_activity (#715)

The sync icon has counter-clockwise arrows by design, making the spin
animation appear counter-clockwise even though CSS rotates clockwise.
Keep play_arrow as the icon in both loading and idle states so the
clockwise spin is visually unambiguous.

src/app/(dashboard)/dashboard/providers/page.js

@@ -267,7 +267,7 @@ export default function ProvidersPage() {
               <span
                 className={`material-symbols-outlined text-[14px]${testingMode === "oauth" ? " animate-spin" : ""}`}
               >
-                {testingMode === "oauth" ? "sync" : "play_arrow"}
+                play_arrow
               </span>
               {testingMode === "oauth" ? "Testing..." : "Test All"}
             </button>
@@ -307,7 +307,7 @@ export default function ProvidersPage() {
             <span
               className={`material-symbols-outlined text-[14px]${testingMode === "free" ? " animate-spin" : ""}`}
             >
-              {testingMode === "free" ? "sync" : "play_arrow"}
+              play_arrow
             </span>
             {testingMode === "free" ? "Testing..." : "Test All"}
           </button>
@@ -356,7 +356,7 @@ export default function ProvidersPage() {
             <span
               className={`material-symbols-outlined text-[14px]${testingMode === "apikey" ? " animate-spin" : ""}`}
             >
-              {testingMode === "apikey" ? "sync" : "play_arrow"}
+              play_arrow
             </span>
             {testingMode === "apikey" ? "Testing..." : "Test All"}
           </button>
@@ -395,7 +395,7 @@ export default function ProvidersPage() {
                 title="Test all Compatible connections"
               >
                 <span className={`material-symbols-outlined text-[14px]${testingMode === "compatible" ? " animate-spin" : ""}`}>
-                  {testingMode === "compatible" ? "sync" : "play_arrow"}
+                  play_arrow
                 </span>
                 {testingMode === "compatible" ? "Testing..." : "Test All"}
               </button>