Add unit tests for handleStateRootError recursion limit

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_test.go

@@ -1313,6 +1313,59 @@ func TestProposer_ComputeStateRoot_OK(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestHandleStateRootError_MaxAttemptsReached(t *testing.T) {
+	// Test that handleStateRootError returns an error when max attempts is reached
+	// instead of recursing infinitely.
+	ctx := t.Context()
+	vs := &Server{}
+
+	// Create a minimal block for testing
+	blk := util.NewBeaconBlock()
+	wsb, err := blocks.NewSignedBeaconBlock(blk)
+	require.NoError(t, err)
+
+	// Pre-seed the context with max attempts already reached
+	ctx = context.WithValue(ctx, computeStateRootAttemptsKey, maxComputeStateRootAttempts)
+
+	// Call handleStateRootError with a retryable error
+	_, err = vs.handleStateRootError(ctx, wsb, transition.ErrAttestationsSignatureInvalid)
+
+	// Should return an error about max attempts instead of recursing
+	require.ErrorContains(t, "attempted max compute state root attempts", err)
+}
+
+func TestHandleStateRootError_IncrementsAttempts(t *testing.T) {
+	// Test that handleStateRootError properly increments the attempts counter
+	// and eventually fails after max attempts.
+	db := dbutil.SetupDB(t)
+	ctx := t.Context()
+
+	beaconState, parentRoot, _ := util.DeterministicGenesisStateWithGenesisBlock(t, ctx, db, 100)
+
+	stateGen := stategen.New(db, doublylinkedtree.New())
+	vs := &Server{
+		StateGen: stateGen,
+	}
+
+	// Create a block that will trigger retries
+	blk := util.NewBeaconBlock()
+	blk.Block.ParentRoot = parentRoot[:]
+	blk.Block.Slot = 1
+	wsb, err := blocks.NewSignedBeaconBlock(blk)
+	require.NoError(t, err)
+
+	// Add a state for the parent root so StateByRoot succeeds
+	require.NoError(t, stateGen.SaveState(ctx, parentRoot, beaconState))
+
+	// Call handleStateRootError with a retryable error - it will recurse
+	// but eventually hit the max attempts limit since CalculateStateRoot
+	// will keep failing (no valid attestations, randao, etc.)
+	_, err = vs.handleStateRootError(ctx, wsb, transition.ErrAttestationsSignatureInvalid)
+
+	// Should eventually fail - either with max attempts or another error
+	require.NotNil(t, err)
+}
+
 func TestProposer_PendingDeposits_Eth1DataVoteOK(t *testing.T) {
 	ctx := t.Context()