feat: add mobile Following queue for watched issues (Closes #1293)

tests/e2e/test_mobile_following_release.py

@@ -0,0 +1,30 @@
+from pathlib import Path
+
+from playwright.sync_api import expect, sync_playwright
+
+
+ROOT = Path(__file__).parents[2]
+FRONTEND = ROOT / "frontend"
+
+
+def test_following_queue_is_phone_usable_at_narrow_viewport():
+    with sync_playwright() as playwright:
+        browser = playwright.chromium.launch(headless=True)
+        page = browser.new_page(viewport={"width": 320, "height": 568})
+        page.set_content((FRONTEND / "index.html").read_text())
+        page.add_style_tag(path=FRONTEND / "dashboard.css")
+
+        row = page.locator('[data-mobile-queue="following"]')
+        expect(row).to_have_count(1)
+        page.locator("#following-list").evaluate("""node => {
+          node.innerHTML = '<button class="following-card" type="button"><span><strong>Quiet issue with a long mobile title</strong><small>stackchain/api #42 · open · just now</small></span><span aria-hidden="true">›</span></button>';
+        }""")
+        page.locator("#following-sheet").evaluate("node => node.showModal()")
+
+        expect(page.locator("#following-sheet")).to_be_visible()
+        expect(page.locator(".following-card")).to_be_visible()
+        assert page.locator(".following-card").bounding_box()["height"] >= 44
+        assert page.locator("#close-following").bounding_box()["height"] >= 44
+        overflow = page.evaluate("document.documentElement.scrollWidth > document.documentElement.clientWidth")
+        assert overflow is False
+        browser.close()