fix: approval windows open as wide as the page (closes #518)

The approval window opened 360 pixels wide while the page is 396, cutting
off the Reject button; it now opens at 396. The browser counts the
window's frame in that width, and a tall screen gives some of it to a
vertical scrollbar, so once the approval's screen is up the page widens
its own window by however far it would scroll sideways, times the zoom of
its own tab. Firefox draws some zoom steps a little larger than it
reports, so the page measures again after each widening, three times at
most. The toolbar popup's window is left alone. The Firefox suite checks
that the sign prompt fits at 170%. README's Visual Style line now gives
the page's real width.

Model: opus-5-5

tests/approvalWindow.test.js

@@ -45,3 +45,132 @@ test("the approval window shows no screen until the background describes the app
     expect(env.visibleViews()).toEqual(["approve-network"]);
     expect(env.pageErrors).toEqual([]);
 });
+
+// The background opens the approval window as wide as the page, but the
+// browser counts the window's frame in that width, and a screen taller than
+// the window takes a vertical scrollbar out of it too
+// (https://git.eeqj.de/sneak/AutistMask/issues/518). The browser suites run
+// without frames, and only the Firefox suite's sign prompt at a zoom other
+// than 100%, so the widening is checked here too.
+//
+// A window 396 screen pixels wide whose page is drawn at `drawn` screen pixels
+// to the page pixel. Widening it gives the page its new width, less the 15
+// screen pixels of the scrollbar the approval screen has, and then calls the
+// page's resize listeners, each of which asked to be called once.
+function windowsStub(type, drawn) {
+    const updates = [];
+    return {
+        updates,
+        getCurrent: (done) => done({ id: 7, type, width: 396 }),
+        update: (id, info, done) => {
+            updates.push({ id, info });
+            done({});
+            globalThis.document.documentElement.clientWidth = Math.floor(
+                (info.width - 15) / drawn,
+            );
+            const resized = globalThis.window.listeners.resize || [];
+            globalThis.window.listeners.resize = [];
+            for (const fn of resized) fn();
+        },
+    };
+}
+
+// The approval page's own tab is at `zoom`. Asked without a tab id, Firefox
+// answers for the window focused last, here a site's tab at 100%.
+function tabsStub(zoom) {
+    return {
+        getCurrent: (done) => done({ id: 11 }),
+        getZoom: (...args) => {
+            const done = args.pop();
+            done(args[0] === 11 ? zoom : 1);
+        },
+    };
+}
+
+// An approval window at `zoom`, `clientWidth` page pixels wide before its
+// screen is up, whose background holds its answer until the test gives it.
+async function bootZoomedApprovalWindow(windows, zoom, clientWidth) {
+    let answer = null;
+    const env = await bootPopup(unversionedValidProfile(), {
+        search: "?approval=approval-1",
+        runtime: {
+            connect: () => ({ postMessage: () => {} }),
+            sendMessage: (msg, reply) => {
+                if (msg.type === "AUTISTMASK_GET_APPROVAL") answer = reply;
+            },
+        },
+        windows,
+        tabs: tabsStub(zoom),
+        documentElement: { scrollWidth: 396, clientWidth },
+    });
+    return { env, answer };
+}
+
+test("at 150% zoom the approval window widens by what its screen lacks, scrollbar included", async () => {
+    const windows = windowsStub("popup", 1.5);
+    // At 150% a window 396 screen pixels wide shows 264 page pixels.
+    const { env, answer } = await bootZoomedApprovalWindow(windows, 1.5, 264);
+
+    // Not before there is a screen to fit.
+    expect(windows.updates).toEqual([]);
+
+    // The screen is taller than the window, so once it is up a vertical
+    // scrollbar takes 15 screen pixels, 10 page pixels at 150%.
+    env.document.documentElement.clientWidth = 254;
+    answer({
+        type: "network",
+        origin: "https://dapp.example",
+        currentNetworkId: "mainnet",
+        requestedNetworkId: "sepolia",
+        isPhishingDomain: false,
+    });
+    await settle();
+
+    // 396 - 254 = 142 page pixels short, which at 150% is 213 screen pixels.
+    // At the 100% of the site's tab it would be 142, and the screen would
+    // still not fit.
+    expect(env.visibleViews()).toEqual(["approve-network"]);
+    expect(windows.updates).toEqual([{ id: 7, info: { width: 609 } }]);
+    expect(env.document.documentElement.clientWidth).toBe(396);
+    expect(env.pageErrors).toEqual([]);
+});
+
+test("at 170% the approval window is widened again while its screen still falls short", async () => {
+    // Firefox reports 170% as 1.7 but draws a page pixel about 1.714 screen
+    // pixels wide, so a window 396 wide shows 231 page pixels.
+    const windows = windowsStub("popup", 1.714);
+    const { env, answer } = await bootZoomedApprovalWindow(windows, 1.7, 231);
+
+    // Less the scrollbar once the screen is up.
+    env.document.documentElement.clientWidth = 222;
+    answer({
+        type: "network",
+        origin: "https://dapp.example",
+        currentNetworkId: "mainnet",
+        requestedNetworkId: "sepolia",
+        isPhishingDomain: false,
+    });
+    await settle();
+
+    // 174 page pixels short, so 296 screen pixels wider at 1.7. That shows 394
+    // page pixels, still 2 short, so 4 screen pixels wider again.
+    expect(windows.updates).toEqual([
+        { id: 7, info: { width: 692 } },
+        { id: 7, info: { width: 696 } },
+    ]);
+    const page = env.document.documentElement;
+    expect(page.scrollWidth).toBeLessThanOrEqual(page.clientWidth);
+    expect(env.pageErrors).toEqual([]);
+});
+
+test("a connection prompt in the toolbar popup leaves the browser window alone", async () => {
+    const windows = windowsStub("normal", 1.5);
+    const { env, answer } = await bootZoomedApprovalWindow(windows, 1.5, 264);
+
+    answer({ origin: "https://dapp.example", isPhishingDomain: false });
+    await settle();
+
+    expect(env.visibleViews()).toEqual(["approve-site"]);
+    expect(windows.updates).toEqual([]);
+    expect(env.pageErrors).toEqual([]);
+});