fix: stabilize v4 component contracts

+labkit/+app/+internal/+launcher/dispatch.m

@@ -297,7 +297,7 @@ function launchSelected()
             addPathIfMissing(app.folder, "-end");
             reportLaunchStage(app, 2, ...
                 "initializing app window via " + app.command);
-            feval(app.command);
+            invokeDiscoveredApp(app);
             setStatus("Finishing startup for " + app.name + "...");
             drawnow;
             setStatus("Opened " + app.command + ".");
@@ -516,7 +516,7 @@ function updateInfo()
 info = struct( ...
     "name", "labkit_launcher", ...
     "displayName", "LabKit App Launcher", ...
-    "version", "1.8.1", ...
+    "version", "1.8.2", ...
     "updated", "2026-07-30");
 end
 
@@ -696,14 +696,47 @@ function addPathIfMissing(folder, varargin)
     addpath(folder, "-begin");
     cleanup = onCleanup(@() rmpath(folder));
 end
+switch string(name)
+    case "manageLabKitVersions"
+        callable = @manageLabKitVersions;
+    case "cleanLabKitArtifacts"
+        callable = @cleanLabKitArtifacts;
+    case "renderLabKitDocs"
+        callable = @renderLabKitDocs;
+    case "runCodecheckReport"
+        callable = @runCodecheckReport;
+    case "profileLabKitTarget"
+        callable = @profileLabKitTarget;
+    case "packageLabKitApp"
+        callable = @packageLabKitApp;
+    otherwise
+        error("labkit:app:internal:launcher:UnknownTool", ...
+            "Launcher tool is not allowlisted: %s", name);
+end
 if nargout > 0
-    [varargout{1:nargout}] = feval(name, varargin{:});
+    [varargout{1:nargout}] = callable(varargin{:});
 else
-    feval(name, varargin{:});
+    callable(varargin{:});
 end
 clear cleanup
 end
 
+function invokeDiscoveredApp(app)
+command = string(app.command);
+resolved = string(which(char(command)));
+expected = fullfile(string(app.folder), command + [".m", ".p"]);
+available = arrayfun(@(candidate) exist(candidate, "file") == 2, expected);
+expected = expected(available);
+if strlength(resolved) == 0 || isempty(expected) || ...
+        ~any(normalizePathEntry(resolved) == normalizePathEntry(expected))
+    error("labkit:app:internal:launcher:AppEntryMismatch", ...
+        "Discovered App entry does not resolve from its owning folder: %s", command);
+end
+% Dynamic extension boundary: the command is derived from and revalidated
+% against one discovered labkit_*_app.m or .p file before invocation.
+feval(char(command));
+end
+
 function apps = discoverApps(root)
 apps = emptyApps();
 roots = [string(fullfile(root, "apps")); privateAppRoots(root)];

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

@@ -263,24 +263,46 @@ function alert(obj, message, title)
         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));
+                labkit.app.internal.NativeAdapterValues.dialogStartFolder( ...
+                "input", startPath));
+            if ~isequal(name, 0)
+                labkit.app.internal.NativeAdapterValues.rememberDialogFolder( ...
+                    "input", folder);
+            end
             result = labkit.app.internal.NativeAdapterValues.dialogPath(name, folder);
         end
 
         function result = chooseInputFolder(~, startPath)
-            folder = uigetdir(labkit.app.internal.NativeAdapterValues.safeStartPath(startPath), "Choose input folder");
+            folder = uigetdir( ...
+                labkit.app.internal.NativeAdapterValues.dialogStartFolder( ...
+                "input", startPath), "Choose input folder");
+            if ~isequal(folder, 0)
+                labkit.app.internal.NativeAdapterValues.rememberDialogFolder( ...
+                    "input", folder);
+            end
             result = labkit.app.internal.NativeAdapterValues.folderDialogPath(folder);
         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));
+                labkit.app.internal.NativeAdapterValues.dialogStartFolder( ...
+                "output", startPath));
+            if ~isequal(name, 0)
+                labkit.app.internal.NativeAdapterValues.rememberDialogFolder( ...
+                    "output", folder);
+            end
             result = labkit.app.internal.NativeAdapterValues.dialogPath(name, folder);
         end
 
         function result = chooseOutputFolder(~, startPath)
-            folder = uigetdir(labkit.app.internal.NativeAdapterValues.safeStartPath(startPath), "Choose output folder");
+            folder = uigetdir( ...
+                labkit.app.internal.NativeAdapterValues.dialogStartFolder( ...
+                "output", startPath), "Choose output folder");
+            if ~isequal(folder, 0)
+                labkit.app.internal.NativeAdapterValues.rememberDialogFolder( ...
+                    "output", folder);
+            end
             result = labkit.app.internal.NativeAdapterValues.folderDialogPath(folder);
         end
     end
@@ -458,7 +480,7 @@ function popoutAllPlots(obj)
 
         function copyAllPlots(obj)
             handles = obj.allAxes();
-            if numel(handles) == 1
+            if isscalar(handles)
                 copygraphics(handles(1), ContentType="image");
             elseif ~isempty(handles)
                 copygraphics(obj.Figure, ContentType="image");
@@ -634,6 +656,8 @@ function chooseFiles(obj, target)
                 return;
             end
             obj.DialogFolders(char(target)) = char(folder);
+            labkit.app.internal.NativeAdapterValues.rememberDialogFolder( ...
+                "input", folder);
             paths = string(folder) + filesep + string(names);
             if config.SelectionMode == "single"
                 paths = paths(1);
@@ -653,6 +677,8 @@ function chooseFolderFiles(obj, target, recursive)
                 return
             end
             obj.DialogFolders(char(target)) = char(folder);
+            labkit.app.internal.NativeAdapterValues.rememberDialogFolder( ...
+                "input", folder);
             paths = labkit.app.internal.NativeAdapterValues.filesInFolder(folder, config.Filters, recursive);
             if recursive && ...
                     numel(paths) > config.FolderWarningThreshold
@@ -691,7 +717,8 @@ function removeSelectedFiles(obj, target, list)
             end
             folder = char(string(configured));
             if isempty(folder) || ~isfolder(folder)
-                folder = labkit.app.internal.NativeAdapterValues.userDialogFolder();
+                folder = labkit.app.internal.NativeAdapterValues.dialogStartFolder( ...
+                    "input", "");
             end
         end
 

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

@@ -21,7 +21,7 @@ function applyFilePaths(~, component, paths)
     if ~isempty(paths)
         if component.UserData.Compact
             text = string(paths(1));
-        elseif numel(paths) == 1
+        elseif isscalar(paths)
             text = "1 file";
         else
             text = string(numel(paths)) + " files";

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

@@ -1,10 +1,16 @@
 function declarations = collectInteractionDeclarations(obj)
 % Class-folder implementation of MatlabPlatformAdapter.collectInteractionDeclarations.
-    declarations = {};
+    chunks = cell(1, numel(obj.Plan.Nodes));
     for k = 1:numel(obj.Plan.Nodes)
         config = obj.Plan.Nodes(k).Configuration;
         if isfield(config, "Interactions")
-            declarations = [declarations config.Interactions];
+            chunks{k} = config.Interactions;
         end
     end
+    populated = ~cellfun("isempty", chunks);
+    if any(populated)
+        declarations = [chunks{populated}];
+    else
+        declarations = cell(1, 0);
+    end
 end

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

@@ -1,4 +1,4 @@
-function list = createFilePanel(obj, node, parent)
+function list = createFilePanel(~, node, parent)
 % Class-folder implementation of MatlabPlatformAdapter.createFilePanel.
     config = node.Configuration;
     panel = uipanel(parent, BorderType="line", ...

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

@@ -36,7 +36,7 @@ function installContentGrid(obj, node, component)
             RowSpacing=policy.ContentSpacing, ...
             ColumnSpacing=policy.ContentSpacing);
         heights = obj.childRowHeights(node.ChildIds);
-        singleGrowable = numel(node.ChildIds) == 1 && ...
+        singleGrowable = isscalar(node.ChildIds) && ...
             obj.isGrowableTabChild(obj.node(node.ChildIds(1)));
         if node.Kind == "workspacePage"
             for k = 1:numel(node.ChildIds)

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

@@ -1,6 +1,8 @@
 function targets = interactionTargetAxes(obj)
 % Class-folder implementation of MatlabPlatformAdapter.interactionTargetAxes.
-    targets = struct("id", {}, "axes", {});
+    capacity = sum(arrayfun(@(node) numel(node.AxisIds), obj.Plan.Nodes));
+    targets = repmat(struct("id", "", "axes", []), 1, capacity);
+    targetCount = 0;
     for k = 1:numel(obj.Plan.Nodes)
         node = obj.Plan.Nodes(k);
         if node.Kind ~= "plotArea"
@@ -9,11 +11,13 @@
         for axisId = node.AxisIds
             key = labkit.app.internal.NativeAdapterValues.axisKey(node.Id, axisId);
             targetId = key;
-            if numel(node.AxisIds) == 1
+            if isscalar(node.AxisIds)
                 targetId = node.Id;
             end
-            targets(end + 1) = struct( ...
+            targetCount = targetCount + 1;
+            targets(targetCount) = struct( ...
                 "id", targetId, "axes", obj.Axes(char(key)));
         end
     end
+    targets = targets(1:targetCount);
 end

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

@@ -1,6 +1,6 @@
 function tf = isGrowableTabChild(obj, node)
 % Class-folder implementation of MatlabPlatformAdapter.isGrowableTabChild.
-    if node.Kind == "section" && numel(node.ChildIds) == 1
+    if node.Kind == "section" && isscalar(node.ChildIds)
         tf = obj.isGrowableTabChild(obj.node(node.ChildIds(1)));
         return
     end

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

@@ -1,12 +1,14 @@
 function selected = nodes(obj, ids)
 % Class-folder implementation of MatlabPlatformAdapter.nodes.
-    selected = repmat(obj.Plan.Nodes(1), 0, 1);
-    for id = string(ids)
+    ids = string(ids);
+    selected = repmat(obj.Plan.Nodes(1), numel(ids), 1);
+    for selectedIndex = 1:numel(ids)
+        id = ids(selectedIndex);
         index = find(string({obj.Plan.Nodes.Id}) == id, 1);
         if isempty(index)
             error("labkit:app:runtime:InvariantFailure", ...
                 "Compiled Layout child is missing: %s.", id);
         end
-        selected(end + 1, 1) = obj.Plan.Nodes(index);
+        selected(selectedIndex, 1) = obj.Plan.Nodes(index);
     end
 end

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

@@ -60,7 +60,7 @@
                 node.Configuration.Layout == "horizontal";
             if node.Kind == "section" && ...
                     ~obj.sectionDrawsOwnTitle(node) && ...
-                    numel(children) == 1
+                    isscalar(children)
                 height = childHeights(1) + ...
                     policy.UntitledSectionChromeHeight;
             elseif obj.usesAdaptiveActionGrid(node)

+labkit/+app/+internal/CompiledDefinition.m

@@ -120,30 +120,41 @@
 end
 
 function bindings = collectSignalBindings(nodes, start)
-bindings = {};
+capacity = sum(cellfun(@(node) numel(node.Signals), nodes)) + ~isempty(start);
+bindings = cell(1, capacity);
+bindingCount = 0;
 for k = 1:numel(nodes)
     signals = nodes{k}.Signals;
     for s = 1:numel(signals)
-        bindings{end + 1} = signals{s};
+        bindingCount = bindingCount + 1;
+        bindings{bindingCount} = signals{s};
     end
 end
 if ~isempty(start)
-    bindings{end + 1} = start;
+    bindingCount = bindingCount + 1;
+    bindings{bindingCount} = start;
 end
+bindings = bindings(1:bindingCount);
 bindings = uniqueBindings(bindings);
 end
 
 function interactions = collectInteractions(nodes)
-interactions = {};
+chunks = cell(1, numel(nodes));
 for k = 1:numel(nodes)
     if nodes{k}.Kind ~= "plotArea"
         continue;
     end
     configuration = nodes{k}.configurationForCompiler();
     if isfield(configuration, "Interactions")
-        interactions = [interactions configuration.Interactions];
+        chunks{k} = configuration.Interactions;
     end
 end
+populated = ~cellfun("isempty", chunks);
+if any(populated)
+    interactions = [chunks{populated}];
+else
+    interactions = cell(1, 0);
+end
 end
 
 function assertUnique(values, label)
@@ -154,17 +165,19 @@ function assertUnique(values, label)
 end
 
 function values = uniqueBindings(values)
-uniqueValues = {};
+uniqueValues = cell(size(values));
+uniqueCount = 0;
 for k = 1:numel(values)
     value = values{k};
     sameId = find(cellfun(@(candidate) candidate.Id == value.Id, ...
-        uniqueValues), 1);
+        uniqueValues(1:uniqueCount)), 1);
     if isempty(sameId)
-        uniqueValues{end + 1} = value;
+        uniqueCount = uniqueCount + 1;
+        uniqueValues{uniqueCount} = value;
     elseif ~isequaln(uniqueValues{sameId}, value)
         error("labkit:app:contract:DuplicateId", ...
             "Layout signal ID %s has conflicting callbacks.", value.Id);
     end
 end
-values = uniqueValues;
+values = uniqueValues(1:uniqueCount);
 end

+labkit/+app/+internal/InteractionSpec.m

@@ -71,7 +71,7 @@
                     obj.Id, missing(1));
             end
             result = obj;
-            if numel(axisIds) == 1
+            if isscalar(axisIds)
                 result.Targets = repmat(plotId, size(obj.AxisIds));
             else
                 result.Targets = plotId + "." + obj.AxisIds;

+labkit/+app/+internal/LayoutNode.m

@@ -452,7 +452,7 @@
         function obj = workspace(varargin)
             content = {};
             if ~isempty(varargin) && isa(varargin{1}, "labkit.app.internal.LayoutNode")
-                content = {varargin{1}};
+                content = varargin(1);
                 varargin = varargin(2:end);
             end
             options = labkit.app.internal.OptionParser.parse( ...
@@ -541,7 +541,7 @@
             labkit.app.internal.LayoutNodeValues.validateChildKinds(content, labkit.app.internal.LayoutNodeValues.workspaceContentKinds(), ...
                 "workspace page");
             pageNode = labkit.app.internal.LayoutNode("workspacePage", id, content, ...
-                ["workspacePage"], {}, [], strings(1, 0), ...
+                "workspacePage", {}, [], strings(1, 0), ...
                 struct("Title", labkit.app.internal.LayoutNodeValues.nonemptyText(title, "workspace page title")));
             obj.Children{end + 1} = pageNode;
             obj.PageIds(end + 1) = id;
@@ -595,7 +595,3 @@
     labkit.app.internal.LayoutNodeValues.optionValue( ...
     options, name, defaultValue), name);
 end
-
-function state = runAnalysis(state, ~)
-    state.finished = true;
-end