Add personal notes, DeepSearch history, backup offload, and gateway auth throttling

Also streamline the top navigation: drop the Tools dropdown, make Quizzes
and Battles icon-only entries, and remove the Workspace, Containers and
Editor entry points from the project detail page.

tests/e2e/feed.py

@@ -1018,6 +1018,35 @@ def test_feed_scroll_not_restored_on_fresh_visit(alice):
     assert page.evaluate("window.scrollY") < 60
 
 
+def test_feed_right_rail_stays_plain_sticky_when_it_fits(alice):
+    page, user = alice
+    page.set_viewport_size({"width": 1400, "height": 2000})
+    page.goto(f"{BASE_URL}/feed", wait_until="domcontentloaded")
+    right = page.locator(".feed-right")
+    right.wait_for(state="visible")
+    page.wait_for_timeout(400)
+    assert right.evaluate("el => el.classList.contains('sticky-scroll-active')") is False
+    assert right.evaluate("el => getComputedStyle(el).maxHeight") == "none"
+
+
+def test_feed_right_rail_scrolls_independently_when_taller_than_viewport(alice):
+    page, user = alice
+    page.set_viewport_size({"width": 1400, "height": 400})
+    page.goto(f"{BASE_URL}/feed", wait_until="domcontentloaded")
+    right = page.locator(".feed-right")
+    right.wait_for(state="visible")
+    page.wait_for_function(
+        "document.querySelector('.feed-right').classList.contains('sticky-scroll-active')"
+    )
+    page.evaluate("window.scrollTo(0, 0)")
+    right.evaluate("el => el.scrollTo(0, el.scrollHeight)")
+    page.wait_for_timeout(200)
+    right_scroll_top = right.evaluate("el => el.scrollTop")
+    window_scroll_y = page.evaluate("window.scrollY")
+    assert right_scroll_top > 0
+    assert window_scroll_y == 0
+
+
 def _seed_post_with_long_code_line(topic="devlog"):
     owner = str(uuid4())
     get_table("users").insert(