refactor(e10): move the platform components into components/ui/ and enforce the boundary

The app HAS a platform layer -- AnchoredPopover (22 importers, with arrows/typeahead/Escape/anchor-flip), QueryState (21), Modal (17), PageShell, DataTable, Tabs, Tooltip and ~26 more -- but it sat flat among ~160 feature components with nothing marking it as one. Several of those files describe themselves as 'the one place' or 'canonical' and were still bypassed by hand-rolled markup, because a layer nobody can see is a layer nobody uses; three separate inventory passes of this codebase misread it the same way. Moves the 33 domain-free modules into components/ui/, rewrites the imports in 89 files, and makes the boundary a lint rule rather than a convention: inside ui/ a one-level-up import (a feature component) and any lib/api slice are errors. The rule was verified to fire on both and to leave generic lib/ helpers alone. README.md states which side of the line a component belongs on and why. No behaviour change: 3x tsc, eslint, knip, prettier and 687 vitest tests all green; no backend file touched.
2026-09-05 16:58:29 +02:00
parent 31fa554b87
commit 5bfcf5d83a
138 changed files with 262 additions and 189 deletions
@@ -0,0 +1,63 @@
+import { useEffect, useRef, useState } from "react";
+import { createPortal } from "react-dom";
+import { ArrowUp } from "lucide-react";
+import { useTranslation } from "react-i18next";
+
+// A floating "back to top" button that fades in once the current page's scroll container is
+// scrolled past a threshold, and smooth-scrolls it back to the top. Every page scrolls inside a
+// <main class="overflow-y-auto"> — the normal pages share App's, the channel page renders its own
+// — so this follows whichever one is mounted. Portaled to <body> so its fixed position is
+// viewport-relative regardless of transformed ancestors.
+export default function BackToTop({ dep, threshold = 600 }: { dep?: unknown; threshold?: number }) {
+  const { t } = useTranslation();
+  const [show, setShow] = useState(false);
+  const scrollerRef = useRef<HTMLElement | null>(null);
+
+  // Listen on the document in the CAPTURE phase and read the scroller off the event, rather than
+  // looking <main> up when this binds. Scroll events don't bubble, but they do capture — and the
+  // lookup was a race the lazy pages lost: on the FIRST visit to the channel page its chunk is
+  // still loading, so the Suspense fallback is on screen, there is no <main> to find, and the
+  // effect gave up for good (its dep never changes again). The button then stayed dead for that
+  // whole visit and came back only once the chunk was cached. Nothing to find, nothing to race.
+  useEffect(() => {
+    const onScroll = (e: Event) => {
+      const el = e.target as HTMLElement | null;
+      if (!el || el.tagName !== "MAIN") return;
+      scrollerRef.current = el;
+      setShow(el.scrollTop > threshold);
+    };
+    document.addEventListener("scroll", onScroll, { passive: true, capture: true });
+    return () => document.removeEventListener("scroll", onScroll, { capture: true });
+  }, [threshold]);
+
+  // On navigation, re-read where the new page sits: usually the top (so hide), but some pages
+  // restore their scroll position. Missing <main> here is now harmless — a page that hasn't
+  // rendered hasn't scrolled either, and the listener above picks it up the moment it does.
+  useEffect(() => {
+    const el = document.querySelector("main");
+    scrollerRef.current = el;
+    setShow(!!el && el.scrollTop > threshold);
+  }, [dep, threshold]);
+
+  const toTop = () =>
+    (scrollerRef.current ?? document.querySelector("main"))?.scrollTo({
+      top: 0,
+      behavior: "smooth",
+    });
+
+  // No aria-label/title attributes: ad-block "annoyance" cosmetic filters (e.g. Brave Shields)
+  // commonly hide floating corner buttons via attribute selectors like [aria-label="Back to top"].
+  // The accessible name comes from a visually-hidden child instead, which those selectors can't match.
+  return createPortal(
+    <button
+      onClick={toTop}
+      className={`fixed bottom-5 right-5 z-chrome inline-flex items-center justify-center w-16 h-16 rounded-full glass-card glass-hover text-fg hover:text-accent transition-all duration-200 ${
+        show ? "opacity-100 translate-y-0" : "opacity-0 translate-y-3 pointer-events-none"
+      }`}
+    >
+      <ArrowUp className="w-7 h-7" aria-hidden="true" />
+      <span className="sr-only">{t("common.backToTop")}</span>
+    </button>,
+    document.body,
+  );
+}