feat(hyperliquid): add stock symbol market data support

- Add Hyperliquid/XYZ symbol normalization tests and backend coverage

- Extend kline and market data lookup paths for US stock symbols

- Wire frontend data API types for stock-oriented market requests

kernel/hyperliquid_rank_test.go

@@ -0,0 +1,15 @@
+package kernel
+
+import "testing"
+
+func TestClampHyperRankLimit(t *testing.T) {
+	if got := clampHyperRankLimit(0); got != 5 {
+		t.Fatalf("clamp 0 = %d, want 5", got)
+	}
+	if got := clampHyperRankLimit(99); got != 10 {
+		t.Fatalf("clamp 99 = %d, want 10", got)
+	}
+	if got := clampHyperRankLimit(3); got != 3 {
+		t.Fatalf("clamp 3 = %d, want 3", got)
+	}
+}