fix: the page menu must not claim a modified key (ChatGPT Codex, PR #123)

The menu's early return sat ABOVE `app.js`'s `metaKey` guard, so with the menu
open `Cmd-R` reached `menuKey`, was answered `ignore`, and was then defaulted
away by `if (!e.ctrlKey && !e.altKey) e.preventDefault()` — true for Meta.
Reload was blocked. `Ctrl-j`/`Alt-Home` had the mirror fault and MOVED the menu,
two lines below a comment saying Ctrl and Alt stay the browser's.

Ordering plus one bail: the `metaKey` guard goes back above the menu branch,
`pageMenuKeydown` returns on `ctrlKey || altKey`, and what remains claims
unconditionally — every unmodified key, `ignore` included, which is the rule the
menu exists to keep.

The harness assertion installs its `defaultPrevented` probe AFTER load so it
runs second and sees what the page decided, and ends on an unmodified `j`
asserting `["j", true]` — without which "nothing was prevented" is satisfied by
a page that claims nothing. Proved by restoring the reviewed code: it fails on
`Control+j` moving the active row.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FC2jVn8Au7E9JPkw6bwXXH

context/test-evidence/clients.md

@@ -3458,3 +3458,32 @@ improvise-wiew's product call, executed. The overlay is open, `]` is pressed,
 and the page bar still reads `Quarter = Q1 (1/4)`. Its sibling — a panel open,
 `]` pressed, bar moves to Q2 *and the panel is still open* — is what stops the
 first one passing because the key does nothing anywhere.
+
+### a modified key is the browser's, and the menu neither acts on it nor claims it
+
+Found by ChatGPT Codex on PR #123, and correct. The page menu's early return
+sat **above** `app.js`'s `metaKey` guard, so with the menu open `Cmd-R` reached
+`menuKey`, was answered `ignore`, and then hit
+`if (!e.ctrlKey && !e.altKey) e.preventDefault()` — which is true for a Meta
+combination. Reload was blocked. `Ctrl-j` and `Alt-Home` had the mirror problem
+in the other direction: they *moved* the menu, although the comment two lines
+below said Ctrl and Alt combinations stay the browser's.
+
+The repair is ordering plus one bail: the `metaKey` guard moves back above the
+menu branch (so the menu is not even consulted), `pageMenuKeydown` returns
+immediately on `ctrlKey || altKey`, and what remains then claims
+**unconditionally** — every unmodified key including `ignore`, which is the rule
+the menu exists to keep.
+
+**Why the assertion is shaped the way it is.** The listener that records
+`defaultPrevented` is installed by `page.evaluate` *after* the page has loaded,
+so it runs **second** on the same target and observes what `app.js` decided. One
+registered first would read `false` for every key and pass against any code at
+all. And the test ends by pressing an **unmodified** `j` and asserting
+`["j", true]`: without that row, "nothing was defaulted away" is equally
+satisfied by a page that claims nothing, so the modifier would not be what the
+test is about.
+
+Fault injected: the reviewed code restored exactly — menu branch above the
+`metaKey` guard, no `ctrlKey || altKey` bail, conditional `preventDefault`. The
+test fails on `Control+j` moving the active row from `✓ Q1` to `  Q2`.

harness/tests/pages.spec.js

@@ -83,6 +83,44 @@ test.describe("a page axis can be picked from a menu", () => {
     await expect(chip(page)).toHaveText(/Quarter = Q2 \(2\/4\)/);
   });
 
+  // Found by ChatGPT Codex on PR #123: the menu branch sat ABOVE the page's
+  // `metaKey` guard, so Cmd-R was answered `ignore` and then defaulted away.
+  test("a modified key is the browser's, and the menu neither acts on it nor claims it", async ({
+    page,
+  }) => {
+    await theDemo(page);
+    // Registered AFTER `app.js`'s own window listener, so it runs second and
+    // reads what the page did — a listener added first would see `false` always.
+    await page.evaluate(() => {
+      window.__claimed = [];
+      window.addEventListener("keydown", (e) =>
+        window.__claimed.push([e.key, e.defaultPrevented]),
+      );
+    });
+    await chip(page).click();
+    await expect(menu(page)).toBeVisible();
+    await expect(menu(page).locator(".page-item.active")).toHaveText("✓ Q1");
+
+    // `Ctrl-j` is not `j`: it must not move the menu the way the bare key does.
+    await page.keyboard.press("Control+j");
+    await expect(menu(page).locator(".page-item.active")).toHaveText("✓ Q1");
+    await page.keyboard.press("Meta+r");
+    await expect(menu(page)).toBeVisible();
+
+    const claimed = await page.evaluate(() => window.__claimed);
+    expect(claimed, `nothing reached the handler: ${JSON.stringify(claimed)}`).not.toEqual([]);
+    for (const [key, prevented] of claimed) {
+      expect(prevented, `${key} was defaulted away; it is the browser's`).toBe(false);
+    }
+
+    // The precondition the rows above lean on: an UNMODIFIED key still is
+    // claimed, so "nothing was prevented" is a fact about the modifier.
+    await page.keyboard.press("j");
+    await expect(menu(page).locator(".page-item.active")).toHaveText("  Q2");
+    const after = await page.evaluate(() => window.__claimed.at(-1));
+    expect(after).toEqual(["j", true]);
+  });
+
   test("Escape closes the menu and changes nothing", async ({ page }) => {
     await theDemo(page);
     await chip(page).click();

web/app.js

@@ -724,6 +724,9 @@ el.grid.addEventListener("mousedown", (event) => {
 /** The menu's own keys, decided in `shell.js`. Every one of them is claimed:
  *  an unhandled key must not reach the grid behind the menu. */
 function pageMenuKeydown(e) {
+  // Ctrl and Alt combinations are the browser's, exactly as below, so the menu
+  // neither acts on one nor claims it — `Ctrl-j` is not `j` (improvise-rw6l).
+  if (e.ctrlKey || e.altKey) return;
   const items = pageAxes[pageMenu.axis].items;
   const action = menuKey(e.key, { count: items.length, active: pageMenu.active });
   if (action.kind === "close") closePageMenu();
@@ -732,23 +735,24 @@ function pageMenuKeydown(e) {
     pageMenu.active = action.item;
     paintPageMenu();
   }
-  // Ctrl and Alt combinations stay the browser's, exactly as below.
+  // Every unmodified key is CLAIMED, `ignore` included: the grid is behind
-  if (!e.ctrlKey && !e.altKey) e.preventDefault();
+  // the menu and must not also act on it.
+  e.preventDefault();
 }
 
 window.addEventListener("keydown", (e) => {
   // The inline editor owns the keyboard while it is open. It stops
   // propagation, so this is belt and braces for a focus we did not predict.
   if (editing) return;
-  // …and so does the page menu, which is the third state of that kind: it is
+  // BrowserKey drops anything held with the platform meta key precisely so
-  // anchored to the grid, so letting `hjkl` through would scroll it away.
+  // Cmd-R does not arrive as a bare `r`; do not claim it here either.
+  if (e.metaKey) return;
+  // …and the page menu owns the keyboard too, which is the third state of
+  // that kind: `hjkl` reaching the grid would scroll it out from under it.
   if (pageMenu) {
     pageMenuKeydown(e);
     return;
   }
-  // BrowserKey drops anything held with the platform meta key precisely so
-  // Cmd-R does not arrive as a bare `r`; do not claim it here either.
-  if (e.metaKey) return;
   // The notice's <summary> is a real control and owns Enter and Space while
   // it has focus. Claiming them here would call `preventDefault` on the
   // browser's own disclosure toggle, so a keyboard visitor could focus it and