fix(374): per-file #nullable enable remediation for UtilitiesCS/Dialogs + misc verify-only files

.claude/agent-memory/atomic-executor/MEMORY.md

@@ -1,5 +1,6 @@
 # Atomic Executor Memory Index
 
+- [Sibling-worktree shared-tooling hazard](project_sibling_worktree_shared_tooling_hazard.md) — a concurrent agent in a DIFFERENT worktree crashes your testhost + clobbers /tmp logs via shared global vstest/dotnet-coverage; use session scratchpad for logs, poll for a quiet machine before test runs, trust bash `$?` not log counts, never kill/commit others' processes/memory files
 - [#375 residuals nullable gotchas](project_375_residuals_nullable_gotchas.md) — CS8644 inherited-interface mismatch from oblivious #366 base fixed with a `#nullable disable` island on the class-declaration line (not `!`); full-solution Rebuild cleans SVGControl.dll → isolated gate CS0006, re-run no-TWAE Build first; MeetingItemHelper Lazy<T> classes: bulk `= null!` + `(...)!` getters/lambdas beats widening the API (Python utf-8-sig for CRLF+BOM files)
 - [#364 nullable-gate pre-existing blockers](project_364_nullable_gate_preexisting_blockers.md) — full-solution pragma-only TWAE gate fails at baseline (vendored SVGControl CS0649 + non-HelperClasses CS0618/CS0168); verify CS86xx via isolated UtilitiesCS build w/ BuildProjectReferences=false; analyzer-version drift needs nuget-install into packages/; coverage script single-assembly StrictMode bug
 

.claude/agent-memory/atomic-executor/project_sibling_worktree_shared_tooling_hazard.md

@@ -0,0 +1,36 @@
+---
+name: sibling-worktree-shared-tooling-hazard
+description: A concurrent agent in a SIBLING worktree corrupts your test runs and temp logs via shared global tooling, even though source is isolated
+metadata:
+  type: project
+---
+
+Two agents in DIFFERENT worktrees (e.g. `.claude/worktrees/agent-XXXX` and
+`TaskMaster-wt/<other-feature>`) share machine-global resources even though their source trees are
+git-isolated. This is distinct from [[project_concurrent_executor_same_worktree]] (same-worktree
+file corruption).
+
+**Why:** Observed on #374 (dialogs-misc) while a sibling agent ran #365 (outlook-folder-store)
+concurrently. Three failure modes, all environmental (not code defects):
+1. **Shared `/tmp`** — MSYS `/tmp` maps to a machine-wide temp dir. Both agents naturally pick the
+   same log filenames (e.g. `/tmp/baseline-tests.log`), so one clobbers the other; you may read the
+   OTHER worktree's output and see its paths/assemblies. Symptom: your log references a foreign
+   worktree path.
+2. **Shared vstest/dotnet-coverage/testhost** — `Invoke-MSTestWithCoverage.ps1` uses global exes.
+   Under concurrent 24-worker (`<Workers>0</Workers>` = auto) coverage runs from both agents, the
+   testhost crashes mid-suite ("Test host process crashed", exit -1/1/127, partial pass counts like
+   522/927/5701 with 0 failures). Nondeterministic.
+
+**How to apply:**
+- Write ALL temp logs to the session scratchpad dir (from the system reminder), NEVER `/tmp`.
+- Before every coverage/test run, poll for a quiet machine and only run when zero
+  `vstest|dotnet-coverage|testhost` processes exist; retry the whole run if it crashes with 0 test
+  failures. A poll-loop (up to ~40×15s) then run, wrapped in an up-to-5-cycle retry, reliably
+  catches a quiet window; a clean run is Total 5702 / Passed 5702 / 0 failed.
+- Trust the bash `$?` exit code (yours), not log-derived counts, when logs may be clobbered. Build
+  gate conclusions on the scoped-build EXIT code (0 = zero CS86xx), which is immune to log
+  contamination.
+- Do NOT kill testhost/vstest/dotnet-coverage processes — you cannot tell yours from the sibling
+  agent's, and killing theirs sabotages them. Just wait.
+- Never stage the sibling/orchestrator's `.claude/agent-memory/orchestrator/*` files (they change
+  under you during the run); leave them untracked/modified and commit only your feature paths.

.claude/agent-memory/orchestrator/MEMORY.md

@@ -48,3 +48,4 @@
 - [Unplanned epic-child worktree mechanics](unplanned-epic-child-worktree-mechanics.md) — cross-worktree delegation works via absolute paths; atomic-executor runs C# tools via pwsh with explicit paths (vstest/csharpier not on PATH); collect_pr_context + PR/merge hooks resolve against session root
 - [Parallel epic children name collisions](parallel-epic-children-name-collisions.md) — siblings coin identical type names in shared namespaces; CS0101/CS0104 surface only at rebase; rename YOUR types, rerun toolchain, no re-review
 - [Swordfish epic F5 ScoDictionary blocker (RESOLVED)](project_swordfish_epic_f5_blocked_on_old_scodictionary.md) — F5 (#308) once WI-0-halted on the OLD ScoDictionary Swordfish base (ScoDictionaryNew was a decoy); #315/PR #316 deleted it, F5 then completed. Lesson: grep the OLD class base + using, not just the *New replacement
+- [Epic-child stale local integration ref](project_epic_child_stale_local_integration_ref.md) — local branch ref for the epic integration branch can be stale in an agent worktree; `git fetch` and branch from `origin/<branch>`, not the bare local name, before trusting a Phase-0 gate

.claude/agent-memory/orchestrator/project_epic_child_stale_local_integration_ref.md

@@ -0,0 +1,32 @@
+---
+name: epic-child-stale-local-integration-ref
+description: Local branch ref for the epic integration branch can be stale in an agent worktree; always git fetch and use origin/<branch> as the tip before branching a child worktree or checking a Phase-0 gate.
+metadata:
+  type: project
+---
+
+For epic-child #374 (utilitiescs-nullable-dialogs-misc), the local ref
+`epic/utilitiescs-nullable-remediation-integration` in the agent worktree
+(`.claude/worktrees/agent-a7e55c484f5d14b45`) resolved to `6d4da8bb...`, an ancestor
+commit that predated PR #379 (#363) and PR #382 (#364) both landing on the branch.
+`git merge-base --is-ancestor` proved `6d4da8bb` was an ancestor of, not equal to,
+`origin/epic/utilitiescs-nullable-remediation-integration` (`dffadd5a...`). Branching
+the child worktree from the stale local ref would have made the Phase-0 gate (checking
+`UtilitiesCS/Extensions/WinFormsExtensions.cs` for `#nullable enable`, proving #363
+Batch D's merge) fail even though the epic orchestrator's briefing correctly stated the
+dependency was merged — the briefing named the right commit, but the local ref hadn't
+caught up to it yet.
+
+**Why:** agent worktrees are created once and their local branch refs are not
+automatically kept current with `origin/*` as sibling epic-child PRs merge over the
+life of the epic. A `git checkout -b <child-branch> <local-integration-branch-name>`
+without a preceding `git fetch origin` silently branches from stale history.
+
+**How to apply:** in any epic-child orchestration, before creating/resetting the child
+worktree branch from the epic integration tip, run `git fetch origin` and use
+`origin/<integration-branch>`'s resolved SHA (not the bare local branch name) as the
+base. Cross-check with `git merge-base --is-ancestor <briefed-commit> origin/<branch>`
+when the briefing names a specific commit SHA for a dependency, to confirm the local
+checkout actually contains it before trusting a Phase-0 gate check performed against
+local refs. See also [[epic-child-pr-gate-gotchas]] and
+[[unplanned-epic-child-worktree-mechanics]].

UtilitiesCS/Dialogs/ActionButton.cs

@@ -8,6 +8,8 @@
 using System.Windows.Forms;
 using UtilitiesCS.Dialogs;
 
+#nullable enable
+
 namespace UtilitiesCS
 {
     public class ActionButton
@@ -91,10 +93,10 @@ Button template
             Button = MakeButton(buttonText, buttonImage, dialogResult);
         }
 
-        private string _name;
-        private Button _button;
+        private string? _name;
+        private Button? _button;
         private Button _template = new DelegateButtonTemplate().Button1; //.Clone();
-        private Action _action;
+        private Action? _action;
 
         public static ActionButton FromButton(
             Button button,
@@ -112,13 +114,13 @@ Action action
 
         public string Name
         {
-            get => _name;
+            get => _name!;
             set => _name = value;
         }
 
         public Button Button
         {
-            get => _button;
+            get => _button!;
             set
             {
                 if (_button != null)
@@ -130,7 +132,7 @@ public Button Button
 
         public Action Delegate
         {
-            get => _action;
+            get => _action!;
             set => _action = value;
         }
 
@@ -180,7 +182,7 @@ private static void AddImageToButton(Image Image, ref Button button)
 
         internal void Button_Click(object sender, EventArgs e)
         {
-            _action.DynamicInvoke();
+            _action!.DynamicInvoke();
         }
     }
 }

UtilitiesCS/Dialogs/DelegateButton.cs

@@ -8,6 +8,8 @@
 using System.Windows.Forms;
 using UtilitiesCS.Dialogs;
 
+#nullable enable
+
 namespace UtilitiesCS
 {
     public class DelegateButton
@@ -90,10 +92,10 @@ Button template
             Button = MakeButton(buttonText, buttonImage, dialogResult);
         }
 
-        private string _name;
-        private Button _button;
+        private string? _name;
+        private Button? _button;
         private Button _template = new DelegateButtonTemplate().Button1.Clone();
-        private Delegate _delegate;
+        private Delegate? _delegate;
 
         public static DelegateButton FromButton(
             Button button,
@@ -111,13 +113,13 @@ Delegate @delegate
 
         public string Name
         {
-            get => _name;
+            get => _name!;
             set => _name = value;
         }
 
         public Button Button
         {
-            get => _button;
+            get => _button!;
             set
             {
                 if (_button != null)
@@ -129,7 +131,7 @@ public Button Button
 
         public Delegate Delegate
         {
-            get => _delegate;
+            get => _delegate!;
             set => _delegate = value;
         }
 
@@ -179,7 +181,7 @@ private static void AddImageToButton(Image Image, ref Button button)
 
         internal void Button_Click(object sender, EventArgs e)
         {
-            _delegate.DynamicInvoke();
+            _delegate!.DynamicInvoke();
         }
     }
 }

UtilitiesCS/Dialogs/DelegateButtonTemplate.cs

@@ -8,6 +8,8 @@
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
+#nullable enable
+
 namespace UtilitiesCS.Dialogs
 {
     public partial class DelegateButtonTemplate : Form

UtilitiesCS/Dialogs/FolderNotFoundViewer.cs

@@ -8,6 +8,8 @@
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
+#nullable enable
+
 namespace UtilitiesCS
 {
     public partial class FolderNotFoundViewer : Form
@@ -17,7 +19,7 @@ public FolderNotFoundViewer()
             InitializeComponent();
         }
 
-        public string FolderAction { get; set; }
+        public string? FolderAction { get; set; }
 
         public string FolderName
         {

UtilitiesCS/Dialogs/FunctionButton.cs

@@ -8,6 +8,8 @@
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
+#nullable enable
+
 namespace UtilitiesCS.Dialogs
 {
     public class FunctionButton<T>
@@ -189,10 +191,10 @@ Button template
             ButtonClickedAsync = function;
         }
 
-        private string _name;
-        private Button _button;
+        private string? _name;
+        private Button? _button;
         private Button _template = new DelegateButtonTemplate().Button1; //.Clone();
-        private Func<T> _function;
+        private Func<T>? _function;
 
         public static FunctionButton<T> FromButton(
             Button button,
@@ -210,13 +212,13 @@ Func<T> function
 
         public string Name
         {
-            get => _name;
+            get => _name!;
             set => _name = value;
         }
 
         public Button Button
         {
-            get => _button;
+            get => _button!;
             [MethodImpl(MethodImplOptions.Synchronized)]
             set
             {
@@ -247,7 +249,7 @@ public Button Button
 
         public Func<T> Delegate
         {
-            get => _function;
+            get => _function!;
             set => _function = value;
         }
 
@@ -295,10 +297,10 @@ private static void AddImageToButton(Image Image, ref Button button)
             button.TextImageRelation = TextImageRelation.ImageBeforeText;
         }
 
-        private Func<T> _buttonClicked;
+        private Func<T>? _buttonClicked;
         public Func<T> ButtonClicked
         {
-            get => _buttonClicked;
+            get => _buttonClicked!;
             [MethodImpl(MethodImplOptions.Synchronized)]
             set
             {
@@ -314,10 +316,10 @@ public Func<T> ButtonClicked
             }
         }
 
-        private Func<Task<T>> _buttonClickedAsync;
+        private Func<Task<T>>? _buttonClickedAsync;
         public Func<Task<T>> ButtonClickedAsync
         {
-            get => _buttonClickedAsync;
+            get => _buttonClickedAsync!;
             set
             {
                 if (_buttonClickedAsync is not null && _button is not null)
@@ -332,7 +334,7 @@ public Func<Task<T>> ButtonClickedAsync
             }
         }
 
-        public T Value { get; internal set; }
+        public T? Value { get; internal set; }
 
         internal void Button_Click(object sender, EventArgs e)
         {

UtilitiesCS/Dialogs/InputBox.cs

@@ -2,6 +2,8 @@
 using System.Threading;
 using System.Windows.Forms;
 
+#nullable enable
+
 namespace UtilitiesCS
 {
     /// <summary>
@@ -66,7 +68,7 @@ internal static Func<InputBoxViewer, DialogResult> DialogInvoker
         /// Side Effects:
         ///     Disposes the viewer form before returning.
         /// </summary>
-        public static string ShowDialog(
+        public static string? ShowDialog(
             string Prompt,
             string Title = "",
             string DefaultResponse = ""

UtilitiesCS/Dialogs/InputBoxViewer.cs

@@ -8,6 +8,8 @@
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
+#nullable enable
+
 namespace UtilitiesCS
 {
     public partial class InputBoxViewer : Form

UtilitiesCS/Dialogs/MyBox.cs

@@ -9,6 +9,8 @@
 using System.Windows.Forms;
 using UtilitiesCS.Dialogs;
 
+#nullable enable
+
 namespace UtilitiesCS
 {
     public enum BoxIcon
@@ -90,7 +92,7 @@ IList<ActionButton> actionButtons
             return result;
         }
 
-        public static T ShowDialog<T>(
+        public static T? ShowDialog<T>(
             MyBoxViewer viewer,
             string Message,
             string Title,
@@ -148,7 +150,7 @@ Dictionary<string, Action> actions
             return ShowDialog(viewer, message, title, icon, actionButtons);
         }
 
-        public static T ShowDialog<T>(
+        public static T? ShowDialog<T>(
             string message,
             string title,
             BoxIcon icon,
@@ -236,7 +238,7 @@ MyBoxViewer _viewer
         public class FunctionButtonGroup<T>
         {
             public List<FunctionButton<T>> FunctionButtons { get; set; } = [];
-            public T Result { get; set; }
+            public T? Result { get; set; }
         }
 
         internal static FunctionButtonGroup<T> ToFunctionButtonsAsync<T>(

UtilitiesCS/Dialogs/MyBoxModeless.cs

@@ -3,6 +3,8 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Windows.Forms;
 
+#nullable enable
+
 namespace UtilitiesCS.Dialogs
 {
     /// <summary>
@@ -65,7 +67,7 @@ internal static void ShowStoreLockupNotification(
             Action disableSessionOnly,
             Action disableForFutureSessions,
             Action reenable,
-            Action<MyBoxViewer> showAction
+            Action<MyBoxViewer>? showAction
         )
         {
             var viewer = new MyBoxViewer();