fix(desktop): retire prepend mode on every reader wheel (#2913)

## Summary

- retire Virtua prepend reconciliation on every ordinary reader wheel
event, including events suppressed from its separate wheel-timing
heuristic
- keep Ctrl+wheel browser zoom excluded from reader ownership
- arm the Ctrl+wheel prepend probe before pagination begins so it cannot
miss the commit
- preserve ESM/CJS patch parity and update the patch lock hash

## Why main was red

PR #2855 added the reader-wheel retirement action after Virtua's
existing suppression guard. Once the first event set that guard, later
events in the same wheel burst returned before retiring prepend mode. A
late ResizeObserver correction could then pull the viewport backward by
20–40px. The same test had failed twice on #2855 but passed its final
retry, so the PR job appeared green; the merge commit lost all three
retries.

The separate Ctrl+wheel failure was a test race: its MutationObserver
was registered after the request had already been triggered and could
miss the prepend commit.

## Validation

- desktop full unit suite: 3,515 passed
- pre-push desktop check: passed
- `git diff --check`: passed
- CI is the E2E verification; no local E2E was run

Fixes the main-branch failure in CI run 30180099007.

Signed-off-by: Wes <wesbillman@users.noreply.github.com>
Co-authored-by: Carl <c7ebe626f000404285d3686e1dc74cc07cc60a9754a150041ba132e14bd3e2ec@buzz.block.builderlab.xyz>

desktop/src/features/messages/ui/virtuaWheelModePatch.test.mjs

@@ -21,7 +21,17 @@ test("reader wheel retires Virtua shift mode without publishing scroll end", ()
       .filter(Boolean),
   );
   assert.deepEqual(addedActionBodies, [["I = 0;"], ["w = 0;"]]);
-  assert.match(patch, /\+\s+e\.q\(9\);/);
+  assert.match(
-  assert.match(patch, /\+\s+e\.B\(9\);/);
+    patch,
+    /if \(!e\.M\(\) \|\| t\.ctrlKey\) return;\n\+\s+e\.q\(9\);\n\+\s+if \(f\) return;/,
+  );
+  assert.match(
+    patch,
+    /if \(!e\.M\(\) \|\| t\.ctrlKey\) return;\n\+\s+e\.B\(9\);\n\+\s+if \(c\) return;/,
+  );
+  assert.doesNotMatch(
+    patch,
+    /\+\s+if \((?:f|c) \|\| !e\.M\(\) \|\| t\.ctrlKey\) return;/,
+  );
   assert.doesNotMatch(patch, /\+\s+e\.(?:q|B)\(2\);/);
 });

desktop/tests/e2e/virtualization.spec.ts

@@ -252,6 +252,29 @@ test.describe("list virtualization", () => {
       });
       await page.waitForTimeout(150);
       const before = await sampleVisibleAnchor();
+      const ctrlWheelPromise =
+        pageIndex === 0
+          ? timeline.evaluate(
+              (scroller) =>
+                new Promise<boolean>((resolve) => {
+                  const s = scroller as HTMLElement;
+                  const observer = new MutationObserver(() => {
+                    observer.disconnect();
+                    // Ctrl+wheel is browser zoom, not reader scroll intent. Fire
+                    // it synchronously with the prepend DOM commit, before the
+                    // ResizeObserver measurement batch reconciles estimated rows.
+                    s.dispatchEvent(
+                      new WheelEvent("wheel", { ctrlKey: true, deltaY: -100 }),
+                    );
+                    resolve(true);
+                  });
+                  observer.observe(s.firstElementChild ?? s, {
+                    childList: true,
+                    subtree: true,
+                  });
+                }),
+            )
+          : Promise.resolve(false);
       const wheelTracePromise = timeline.evaluate(async (scroller) => {
         const s = scroller as HTMLElement;
         let previousScrollTop = s.scrollTop;
@@ -297,25 +320,8 @@ test.describe("list virtualization", () => {
       });
       const committedAnchor = await sampleVisibleAnchor(before.id);
       const motion = await timeline.evaluate(
-        async (scroller, { anchorId, anchorTop, oldHeight, testCtrlWheel }) => {
+        async (scroller, { anchorId, anchorTop, oldHeight }) => {
           const s = scroller as HTMLElement;
-          let ctrlWheelDispatched = false;
-          const mutationObserver = testCtrlWheel
-            ? new MutationObserver(() => {
-                if (ctrlWheelDispatched) return;
-                ctrlWheelDispatched = true;
-                // Ctrl+wheel is browser zoom, not reader scroll intent. Fire it
-                // synchronously with the prepend DOM commit, before the
-                // ResizeObserver measurement batch reconciles estimated rows.
-                s.dispatchEvent(
-                  new WheelEvent("wheel", { ctrlKey: true, deltaY: -100 }),
-                );
-              })
-            : null;
-          mutationObserver?.observe(s.firstElementChild ?? s, {
-            childList: true,
-            subtree: true,
-          });
           let maxDrift = 0;
           let sawPrepend = false;
           let sawAnchorAfterPrepend = false;
@@ -343,20 +349,16 @@ test.describe("list virtualization", () => {
             if (sawAnchorAfterPrepend && stableFrames >= 8) break;
             await new Promise((resolve) => requestAnimationFrame(resolve));
           }
-          mutationObserver?.disconnect();
+          return { maxDrift, sawPrepend };
-          return { ctrlWheelDispatched, maxDrift, sawPrepend };
         },
         {
           anchorId: committedAnchor.id,
           anchorTop: committedAnchor.top,
           oldHeight: before.scrollHeight,
-          // Exercise browser-zoom input once while a real prepend transaction
-          // still owns its measurement reconciliation.
-          testCtrlWheel: pageIndex === 0,
         },
       );
       expect(motion.sawPrepend).toBe(true);
-      if (pageIndex === 0) expect(motion.ctrlWheelDispatched).toBe(true);
+      if (pageIndex === 0) expect(await ctrlWheelPromise).toBe(true);
       expect(motion.maxDrift).toBeLessThan(5);
 
       await expect

patches/virtua@0.49.3.patch

@@ -54,11 +54,13 @@ index e02dfd0b3db60faff2cc705d7ce0aa51cb958f5a..b12677a356f748ebccf6e16cb781efe1
              }
              l && (d = 1 + (2147483647 & d), o && z && ($ += z, z = 0), O.forEach(([e, t]) => {
                  l & e && t(n);
-@@ -186,6 +198,7 @@ const r = null, {min: n, max: s, abs: i, floor: l} = Math, c = (e, t, o) => n(o,
+@@ -186,6 +198,8 @@ const r = null, {min: n, max: s, abs: i, floor: l} = Math, c = (e, t, o) => n(o,
          c = l(), d && (a = !0), i && e.q(6, i()), e.q(1, n()), h();
      }, p = t => {
-         if (f || !e.M() || t.ctrlKey) return;
+-        if (f || !e.M() || t.ctrlKey) return;
++        if (!e.M() || t.ctrlKey) return;
 +        e.q(9);
++        if (f) return;
          const r = l() - c;
          150 > r && 50 < r && (o ? t.deltaX : t.deltaY) && (f = !0);
      }, v = () => {
@@ -150,11 +152,13 @@ index 110ac3858a002a6cdb698da2b56350bc1bf609d2..db83efc83fb3b6d7aa07d83b7463d6ed
              }
              d && (i = 1 + (2147483647 & i), o && p && (g += p, p = 0), O.forEach(([e, t]) => {
                  d & e && t(n);
-@@ -190,6 +202,7 @@ const u = null, {min: d, max: a, abs: h, floor: g} = Math, p = (e, t, o) => d(o,
+@@ -190,6 +202,8 @@ const u = null, {min: d, max: a, abs: h, floor: g} = Math, p = (e, t, o) => d(o,
          l = i(), d && (a = !0), s && e.B(6, s()), e.B(1, n()), h();
      }, p = t => {
-         if (c || !e.M() || t.ctrlKey) return;
+-        if (c || !e.M() || t.ctrlKey) return;
++        if (!e.M() || t.ctrlKey) return;
 +        e.B(9);
++        if (c) return;
          const n = i() - l;
          150 > n && 50 < n && (o ? t.deltaX : t.deltaY) && (c = !0);
      }, v = () => {

pnpm-lock.yaml

@@ -9,7 +9,7 @@ overrides:
 
 patchedDependencies:
   isomorphic-git: e9b414a60d4cf1d8aa18f7a779483984e821989967c235662566e94ef0238d3f
-  virtua@0.49.3: 63923c1f0c73f6fd487c788159fe2f1bd6930e5aeebe815cc511c1c4747294bc
+  virtua@0.49.3: 30a7a92b94800ec37be8d36546ea98c04a05dcd0637f9fac27a06f016ba2eff4
 
 importers:
 
@@ -232,7 +232,7 @@ importers:
         version: 2.1.0
       virtua:
         specifier: 0.49.3
-        version: 0.49.3(patch_hash=63923c1f0c73f6fd487c788159fe2f1bd6930e5aeebe815cc511c1c4747294bc)(react-dom@19.2.7(react@19.2.7))(react@19.2.7)
+        version: 0.49.3(patch_hash=30a7a92b94800ec37be8d36546ea98c04a05dcd0637f9fac27a06f016ba2eff4)(react-dom@19.2.7(react@19.2.7))(react@19.2.7)
       yaml:
         specifier: ^2.8.3
         version: 2.9.0
@@ -6926,7 +6926,7 @@ snapshots:
       '@types/unist': 3.0.3
       vfile-message: 4.0.3
 
-  virtua@0.49.3(patch_hash=63923c1f0c73f6fd487c788159fe2f1bd6930e5aeebe815cc511c1c4747294bc)(react-dom@19.2.7(react@19.2.7))(react@19.2.7):
+  virtua@0.49.3(patch_hash=30a7a92b94800ec37be8d36546ea98c04a05dcd0637f9fac27a06f016ba2eff4)(react-dom@19.2.7(react@19.2.7))(react@19.2.7):
     optionalDependencies:
       react: 19.2.7
       react-dom: 19.2.7(react@19.2.7)