drmoisan · drmoisan · Aug 22, 2026 · Aug 22, 2026 · Aug 22, 2026 · Aug 22, 2026
diff --git a/.claude/agent-memory/feature-review/MEMORY.md b/.claude/agent-memory/feature-review/MEMORY.md
@@ -1,3 +1,4 @@
+- [verify-zero-own-effect-coverage-noise-491](project_verify-zero-own-effect-coverage-noise-491.md) — verify "coverage shortfall is noise" claims: grep both Cobertura XMLs for the changed assembly (zero-effect proof), diff-check attributed unrelated files, distrust deleted-raw-XML "reproducibility" narratives (#491)
 - [poshqc-bundled-coverage-artifact-reads-zero](project_poshqc-bundled-coverage-artifact-reads-zero.md) — run_poshqc_test writes the canonical artifacts/pester/powershell-coverage.xml with 0 covered lines (invalid capture) → honest FAIL row, non-blocking; adjudicate from committed direct-Pester JaCoCo (#441)
 - [441-review-residuals-and-494-handoff](project_441-review-residuals-and-494-handoff.md) — #441 PASS/0 blocking; 85.0317% vs 85% margin is #494's decision; NF-1 uncovered Helpers.ps1:220; NF-2 tooling filing owed; #529-#532 OPEN, deliberately unfixed
 - [nullable-remediation-epic-review-pattern](project_nullable-remediation-epic-review-pattern.md) — utilitiescs-nullable epic children (#363+): epic-integration diff base, per-file #nullable enable, net481; solution gate fails on pre-existing warnings — use per-project AC1 proof

diff --git a/...gent-memory/feature-review/project_verify-zero-own-effect-coverage-noise-491.md b/...gent-memory/feature-review/project_verify-zero-own-effect-coverage-noise-491.md
@@ -0,0 +1,32 @@
+---
+name: verify-zero-own-effect-coverage-noise-491
+description: technique for independently verifying a "coverage shortfall has zero own-effect" claim from dual committed Cobertura XMLs, used on #491
+metadata:
+  type: project
+---
+
+When an executor claims a post-change coverage shortfall is environmental noise unrelated to the
+change (rather than a real regression), verify it directly from the two committed Cobertura XML
+files rather than accepting the narrative:
+
+1. Confirm root `<coverage lines-covered=... lines-valid=...>` attributes match the claimed
+   baseline/post-change numbers exactly, and that `lines-valid` (denominator) is identical between
+   the two files (proves same instrumented surface).
+2. For "zero own-effect" claims (e.g. the changed files are in an excluded/uninstrumented
+   assembly), grep both XML files for the changed assembly's `name="..."` and `filename="..."`
+   patterns — zero matches in both files is direct proof of zero own-effect, not just an assertion
+   about the harness's documented exclusion policy.
+3. For "attributed to unrelated file X" claims, extract that file's `<class line-rate=...>` node
+   from both XML files and confirm a real numeric drop; then `git diff --name-only <base> <head>`
+   to confirm X is not in the branch's diff.
+4. If the executor ran multiple diagnostic capture attempts but deleted the raw XML for all but the
+   canonical one, treat only the canonical (officially-cited) capture as verified; disclose the
+   others as narrative-only corroboration in the audit rather than silently accepting "reproducible
+   across N runs" as proven.
+
+This four-step check let a #491 AC10 shortfall (85.5627% vs 85.5788% baseline, -10 lines) be
+dispositioned non-blocking on independently verified evidence rather than on trust: zero
+`QuickFiler.Test` occurrences in either Cobertura file, and the entire shortfall traced to
+`SegmentStopWatch.cs` + `OlTableExtensions.Etl.cs`, both confirmed absent from the branch diff.
+
+Related: [csharp-coverage-constants-nondeterministic], [jacoco-summary-substitution-is-valid-coverage-evidence].
diff --git a/QuickFiler.Test/Controllers/QfcHomeControllerTests.cs b/QuickFiler.Test/Controllers/QfcHomeControllerTests.cs
@@ -240,17 +240,6 @@ await _controller.InitAsync(
             );
         }
 
-        public class QfcFormViewerDerived : QfcFormViewer
-        {
-            public QfcFormViewerDerived()
-                : base() { }
-
-            public new virtual void Show() => base.Show();
-
-            //public new virtual DialogResult ShowDialog() => base.ShowDialog();
-            public new virtual FormWindowState WindowState { get; set; }
-        }
-
         //[TestMethod]
         //public void QuickFileMetrics_WRITE_ExecutesCorrectly()
         //{

diff --git a/QuickFiler.Test/Form1.Designer.cs b/QuickFiler.Test/Form1.Designer.cs
diff --git a/QuickFiler.Test/Form1.cs b/QuickFiler.Test/Form1.cs