help loading images into layers by filename

@joshakatz 

Try the following script, it is designed to work with open PSD files (you didn't answer my question if they were PSD).

It is presumed and required that all open PSD files have been previously saved (so that there is a backing path to the file on the drive), otherwise, the script may be interrupted. It is also presumed that the JPEG file name matches the PSD with the addition of "_retouched.jpg". If the path to the retouched JPEG folder is always the same, this could be coded into the script rather than being asked to select the folder.

/*
Layer & Save Matching Retouched JPEG over All Open PSD Files.jsx
v1.0 - 7th May 2023, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-discussions/help-loading-images-into-layers-by-filename/td-p/13769691
Notes:
All open files should have been previously saved, unsaved files may interrupt the batch processing
JPEG file names must match the open PSD name, with the addition of "_retouched.jpg" at the end of the doc name
*/

#target photoshop

if (app.documents.length > 0) {
    (function () {
        var jpgFolder = Folder.selectDialog('Please select the retouched JPEG folder:');
        if (jpgFolder === null) return;
        var psdOptions = new PhotoshopSaveOptions();
        psdOptions.embedColorProfile = true;
        psdOptions.alphaChannels = true;
        psdOptions.layers = true;
        psdOptions.spotColors = true;
        var savedDisplayDialogs = app.displayDialogs;
        app.displayDialogs = DialogModes.NO;
        while (app.documents.length > 0) {
            if (activeDocument.path) {
                var psdName = activeDocument.name.replace(/\.[^\.]+$/, '');
                var jpgName = psdName + "_retouched.jpg";
                var jpgFile = jpgFolder + '/' + jpgName;
                placeFile(File(jpgFile), 100);
                activeDocument.activeLayer.rasterize(RasterizeType.ENTIRELAYER);
                activeDocument.saveAs(new File(activeDocument.fullName), psdOptions);
                activeDocument.close(SaveOptions.DONOTSAVECHANGES);
            } else {
                alert("The file has never been saved!");
            }
        }
        app.displayDialogs = savedDisplayDialogs;
        app.beep();
    })();
}
else {
    alert('One or more previously saved docs must be open to use this script!');
}

function placeFile(file, scale) {
    try {
        var idPlc = charIDToTypeID("Plc ");
        var desc2 = new ActionDescriptor();
        var idnull = charIDToTypeID("null");
        desc2.putPath(idnull, new File(file));
        var idFTcs = charIDToTypeID("FTcs");
        var idQCSt = charIDToTypeID("QCSt");
        var idQcsa = charIDToTypeID("Qcsa");
        desc2.putEnumerated(idFTcs, idQCSt, idQcsa);
        var idOfst = charIDToTypeID("Ofst");
        var desc3 = new ActionDescriptor();
        var idHrzn = charIDToTypeID("Hrzn");
        var idPxl = charIDToTypeID("#Pxl");
        desc3.putUnitDouble(idHrzn, idPxl, 0.000000);
        var idVrtc = charIDToTypeID("Vrtc");
        var idPxl = charIDToTypeID("#Pxl");
        desc3.putUnitDouble(idVrtc, idPxl, 0.000000);
        var idOfst = charIDToTypeID("Ofst");
        desc2.putObject(idOfst, idOfst, desc3);
        var idWdth = charIDToTypeID("Wdth");
        var idPrc = charIDToTypeID("#Prc");
        desc2.putUnitDouble(idWdth, idPrc, scale);
        var idHght = charIDToTypeID("Hght");
        var idPrc = charIDToTypeID("#Prc");
        desc2.putUnitDouble(idHght, idPrc, scale);
        var idAntA = charIDToTypeID("AntA");
        desc2.putBoolean(idAntA, true);
        executeAction(idPlc, desc2, DialogModes.NO);
    } catch (e) { }
}

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

I must have forgotten my jellyfish pills. I can't picture what you're trying to do.

OPTION 1:  Photoshop can make a contact sheet.

Go to File > Automate > Contact Sheet II > load images and sort by file name.

OPTION 2: Create a single file with multiple images stacked in layers.

File > Scripts > Load files into Stack.