fix: restore cross-platform batch crop workflows

+labkit/+app/+internal/@MatlabPlatformAdapter/MatlabPlatformAdapter.m

@@ -261,6 +261,7 @@ function alert(obj, message, title)
         end
 
         function result = chooseInputFile(~, filters, startPath)
+            filters = labkit.app.internal.NativeAdapterValues.dialogFilters(filters);
             [name, folder] = uigetfile(filters, "Choose input file", ...
                 labkit.app.internal.NativeAdapterValues.safeStartPath(startPath));
             result = labkit.app.internal.NativeAdapterValues.dialogPath(name, folder);
@@ -272,6 +273,7 @@ function alert(obj, message, title)
         end
 
         function result = chooseOutputFile(~, filters, startPath)
+            filters = labkit.app.internal.NativeAdapterValues.dialogFilters(filters);
             [name, folder] = uiputfile(filters, "Choose output file", ...
                 labkit.app.internal.NativeAdapterValues.safeStartPath(startPath));
             result = labkit.app.internal.NativeAdapterValues.dialogPath(name, folder);

+labkit/+app/+internal/NativeAdapterValues.m

@@ -390,7 +390,7 @@ function restoreViewport(axes, viewport)
         end
 
         function value = dialogFilters(filters)
-        filters = string(filters(:));
+        filters = textColumn(filters);
         if isempty(filters)
             value = "*.*";
         elseif mod(numel(filters), 2) == 0
@@ -401,7 +401,7 @@ function restoreViewport(axes, viewport)
         end
 
         function paths = filesInFolder(folder, filters, recursive)
-        filters = string(filters(:));
+        filters = textColumn(filters);
         if mod(numel(filters), 2) == 0
             filters = filters(1:2:end);
         end
@@ -467,11 +467,11 @@ function restoreViewport(axes, viewport)
         end
 
         function labels = formatFileLabels(paths, statuses)
-        paths = string(paths(:));
+        paths = textColumn(paths);
         if nargin < 2 || isempty(statuses)
             statuses = strings(size(paths));
         else
-            statuses = string(statuses(:));
+            statuses = textColumn(statuses);
         end
         if numel(statuses) ~= numel(paths)
             error("labkit:app:contract:InvalidValue", ...
@@ -551,3 +551,13 @@ function restoreViewport(axes, viewport)
 
     end
 end
+
+function values = textColumn(values)
+if isempty(values)
+    values = strings(0, 1);
+elseif ischar(values)
+    values = string(values);
+else
+    values = string(values(:));
+end
+end

+labkit/+app/+internal/PortableSourceStore.m

@@ -369,7 +369,13 @@ function validateRecord(record)
 if ~(ischar(value) || isstring(value) || iscellstr(value))
     invalid("Source paths must be text.");
 end
-paths = string(value(:));
+if isempty(value)
+    paths = strings(0, 1);
+elseif ischar(value)
+    paths = string(value);
+else
+    paths = string(value(:));
+end
 if any(strlength(paths) == 0)
     invalid("Source paths must be nonempty.");
 end

+labkit/+app/+internal/RuntimeKernel.m

@@ -192,20 +192,50 @@ function setTraceCapture(obj, enabled)
             catch cause
                 obj.Recorder.finish( ...
                     operation, "failed", "notApplicable", cause);
-                rethrow(cause);
+                destination = obj.exportDiagnosticTextFallback( ...
+                    destination, cause);
             end
         end
 
         function destination = exportDiagnosticBundleInteractive(obj)
-            choice = obj.Context.chooseOutputFile( ...
-                {"*.zip", "Diagnostic bundle (*.zip)"}, ...
-                "labkit-diagnostics.zip");
             destination = "";
+            try
+                choice = obj.Context.chooseOutputFile( ...
+                    {"*.zip", "Diagnostic bundle (*.zip)"}, ...
+                    "labkit-diagnostics.zip");
+            catch cause
+                destination = obj.exportDiagnosticTextFallback("", cause);
+                obj.alertDiagnosticTextFallback(destination);
+                return;
+            end
             if ~choice.Cancelled
                 destination = obj.exportDiagnosticBundle(choice.Value);
+                if endsWith(destination, ".txt", ...
+                        IgnoreCase=true)
+                    obj.alertDiagnosticTextFallback(destination);
+                end
             end
         end
 
+        function destination = exportDiagnosticTextFallback( ...
+                obj, preferredDestination, cause)
+            obj.Recorder.log( ...
+                "warning", "diagnostics.text_fallback.started", ...
+                "Diagnostic ZIP export failed; writing a plain-text fallback.", ...
+                Category="runtime.lifecycle", Audience="user", ...
+                Exception=cause);
+            destination = obj.Recorder.exportTextFallback( ...
+                preferredDestination, cause);
+        end
+
+        function alertDiagnosticTextFallback(obj, destination)
+            obj.Context.alert( ...
+                "The diagnostic ZIP could not be exported. A plain-text " + ...
+                "diagnostic fallback was written to:" + newline + ...
+                string(destination), ...
+                "Diagnostic Text Fallback");
+        end
+
         function supported = supportsSyntheticInputs(obj)
             supported = ~isempty(obj.Application.BuildSyntheticSample);
         end

+labkit/+app/+internal/SessionDiagnosticBundle.m

@@ -51,6 +51,29 @@
             end
             clear zipCleanup cleanup
         end
+
+        function destination = writeFallback(snapshot, preferredDestination)
+            % RuntimeKernel supplies sanitized in-memory records. Prefer a
+            % surviving selected folder, then MATLAB's writable temp folder.
+            snapshot = validateFallbackSnapshot(snapshot);
+            folders = fallbackFolders(preferredDestination);
+            failure = [];
+            for index = 1:numel(folders)
+                destination = availableFallbackPath(folders(index));
+                try
+                    writeText(destination, fallbackLines(snapshot));
+                    return;
+                catch cause
+                    failure = cause;
+                end
+            end
+            if isempty(failure)
+                error("labkit:app:runtime:DiagnosticWriteFailed", ...
+                    "No diagnostic text fallback folder is available.");
+            end
+            error("labkit:app:runtime:DiagnosticWriteFailed", ...
+                "Could not write the diagnostic text fallback.");
+        end
     end
 end
 
@@ -101,6 +124,30 @@ function validateRecord(record)
     record.attributes);
 end
 
+function snapshot = validateFallbackSnapshot(snapshot)
+fields = ["application", "events", "capture", "failureIdentifier"];
+if ~isstruct(snapshot) || ~isscalar(snapshot) || ...
+        ~isequal(string(fieldnames(snapshot)), fields.') || ...
+        ~isstruct(snapshot.application) || ...
+        ~isscalar(snapshot.application) || ...
+        ~isstruct(snapshot.capture) || ~isscalar(snapshot.capture)
+    error("labkit:app:runtime:InvariantFailure", ...
+        "Diagnostic text fallback snapshot is invalid.");
+end
+if isempty(snapshot.events)
+    snapshot.events = emptyEvents();
+elseif ~isstruct(snapshot.events)
+    error("labkit:app:runtime:InvariantFailure", ...
+        "Diagnostic text fallback events are invalid.");
+else
+    for index = 1:numel(snapshot.events)
+        validateRecord(snapshot.events(index));
+    end
+    [~, order] = sort(double([snapshot.events.sequence]));
+    snapshot.events = snapshot.events(order);
+end
+end
+
 function destination = diagnosticZipPath(destination)
 if ~(ischar(destination) || ...
         (isstring(destination) && isscalar(destination))) || ...
@@ -144,6 +191,106 @@ function validateRecord(record)
     ];
 end
 
+function value = fallbackLines(snapshot)
+application = snapshot.application;
+capture = snapshot.capture;
+value = [
+    "LabKit Diagnostic Text Fallback"
+    ""
+    "The normal diagnostic ZIP could not be written. This single text file contains the surviving privacy-safe Runtime session records."
+    "It does not contain projects, scientific inputs or results, images, screenshots, source files, paths, or original filenames."
+    ""
+    "Application:"
+    "- Name: " + textField(application, "title")
+    "- App ID: " + textField(application, "appId")
+    "- App version: " + textField(application, "appVersion")
+    "- LabKit App SDK version: " + ...
+        textField(application, "labkitAppVersion")
+    "- ZIP failure identifier: " + string(snapshot.failureIdentifier)
+    ""
+    "Capture notes:"
+    "- TRACE enabled at fallback: " + ...
+        yesNo(logicalField(capture, "traceEnabled"))
+    "- In-memory live view truncated: " + ...
+        yesNo(logicalField(capture, "inMemoryTruncated"))
+    "- Retained canonical event count: " + ...
+        string(numel(snapshot.events))
+    ""
+    "Session timeline:"
+    timeline(snapshot.events)
+    ""
+    "Structured failure records:"
+    fallbackErrorLines(snapshot.events)
+    ];
+end
+
+function value = fallbackErrorLines(events)
+records = errorRecords(events);
+if isempty(records)
+    value = "(none)";
+    return;
+end
+value = strings(numel(records), 1);
+for index = 1:numel(records)
+    value(index) = string(jsonencode(records(index)));
+end
+end
+
+function value = textField(structure, name)
+if isfield(structure, name)
+    value = string(structure.(name));
+else
+    value = "unknown";
+end
+end
+
+function value = logicalField(structure, name)
+value = false;
+if isfield(structure, name) && isscalar(structure.(name))
+    value = logical(structure.(name));
+end
+end
+
+function folders = fallbackFolders(preferredDestination)
+folders = strings(0, 1);
+if ischar(preferredDestination) || ...
+        (isstring(preferredDestination) && isscalar(preferredDestination))
+    preferredDestination = strip(string(preferredDestination));
+    if strlength(preferredDestination) > 0
+        folder = string(fileparts(preferredDestination));
+        if strlength(folder) == 0
+            folder = string(pwd);
+        end
+        if exist(char(folder), "dir") == 7
+            folders(end + 1, 1) = folder;
+        end
+    end
+end
+temporaryFolder = string(tempdir);
+if exist(char(temporaryFolder), "dir") == 7
+    folders(end + 1, 1) = temporaryFolder;
+end
+folders = unique(folders, "stable");
+end
+
+function destination = availableFallbackPath(folder)
+destination = fullfile(folder, "labkit-diagnostics-fallback.txt");
+if exist(char(destination), "file") ~= 2 && ...
+        exist(char(destination), "dir") ~= 7
+    return;
+end
+for index = 2:1000
+    candidate = fullfile(folder, ...
+        "labkit-diagnostics-fallback-" + string(index) + ".txt");
+    if exist(char(candidate), "file") ~= 2 && ...
+            exist(char(candidate), "dir") ~= 7
+        destination = candidate;
+        return;
+    end
+end
+destination = string(tempname(char(folder))) + ".txt";
+end
+
 function value = timeline(events)
 value = strings(numel(events), 1);
 for index = 1:numel(events)

+labkit/+app/+internal/SessionDiagnostics.m

@@ -144,6 +144,44 @@ function setTraceEnabled(obj, enabled)
                 snapshot, destination);
         end
 
+        function destination = exportTextFallback( ...
+                obj, preferredDestination, failure)
+            % Keep this path independent of the journal and ZIP staging so a
+            % failure in either subsystem cannot consume the last evidence.
+            try
+                streamSnapshot = obj.Stream.captureSnapshot();
+                events = streamSnapshot.events;
+                capture = struct( ...
+                    "traceEnabled", streamSnapshot.traceEnabled, ...
+                    "inMemoryTruncated", ...
+                        streamSnapshot.inMemoryTruncated);
+            catch
+                events = [];
+                capture = struct( ...
+                    "traceEnabled", false, ...
+                    "inMemoryTruncated", true);
+            end
+            sdk = labkit.app.version();
+            application = struct( ...
+                "title", obj.Application.Title, ...
+                "appId", obj.Application.AppId, ...
+                "appVersion", obj.Application.AppVersion, ...
+                "labkitAppVersion", string(sdk.current));
+            failureIdentifier = "unknown";
+            if isa(failure, "MException") && ...
+                    strlength(string(failure.identifier)) > 0
+                failureIdentifier = string(failure.identifier);
+            end
+            snapshot = struct( ...
+                "application", application, ...
+                "events", events, ...
+                "capture", capture, ...
+                "failureIdentifier", failureIdentifier);
+            destination = ...
+                labkit.app.internal.SessionDiagnosticBundle.writeFallback( ...
+                snapshot, preferredDestination);
+        end
+
         function close(obj)
             if obj.Closed
                 return;

+labkit/+app/+internal/SessionEventValidator.m

@@ -293,7 +293,10 @@ function rejectSensitiveAttributeKey(key, value)
 end
 
 function count = maximumRetainedAttributeKeyLength()
-count = 64;
+% R2022b truncates MATLAB identifiers after 63 characters. Attribute keys
+% arrive as struct field names, so the portable contract cannot exceed that
+% floor even when a newer MATLAB reports a larger namelengthmax.
+count = 63;
 end
 
 function count = maximumRetainedSemanticTokenLength()

+labkit/+app/CallbackContext.m

@@ -204,6 +204,10 @@ function saveRecoveryDocument(obj, state, filepath)
             elseif ~(ischar(ids) || isstring(ids) || iscellstr(ids))
                 error("labkit:app:contract:InvalidValue", ...
                     "CallbackContext source ids must be text.");
+            elseif isempty(ids)
+                ids = strings(0, 1);
+            elseif ischar(ids)
+                ids = string(ids);
             else
                 ids = string(ids(:));
             end

+labkit/+app/version.m

@@ -30,6 +30,6 @@
 %   labkit.app.Definition
 
     info = labkit.contract.versionInfo( ...
-        "app", "2.0.1", ">=2 <3", "stable", ...
+        "app", "2.0.3", ">=2 <3", "stable", ...
         "Explicit LabKit App SDK contract for tracked production Apps.");
 end