refactor(ui): shared FilterChipGroup; unify feed filter chips (R13 S2c step 2)

New single-select FilterChipGroup primitive on the canonical rounded-full
"Filters bar" chip look (pill + shadow-xs + press feedback), plus an exported
filterChipClass so multi-select siblings share ONE geometry source of truth.

Migrations:
- feed watch-state chips (F1, Feed.tsx) -> FilterChipGroup, testIds preserved
- feed content-type toggles restyled to filterChipClass (stay multi-select) so
  the whole toolbar row is one chip look; wrapped in their own labelled group
- feed date presets + Custom (F3, Sidebar.tsx) -> FilterChipGroup with a
  behaviour-preserving dispatch (preset toggle-off + Custom editor intact)

Adds aria-label i18n (feed.showLabel/contentLabel, sidebar.datePresetLabel;
HU+EN) and FilterChipGroup.dom.test.tsx (6 tests). Self-E2E'd: watch switch,
date preset on/off toggle, Custom opens the range editor. gate green (vitest
136, tsc/eslint-0/knip/prettier). Branch not merged.

frontend/src/components/Feed.tsx

@@ -40,6 +40,7 @@ import { LoadingState, StateMessage } from "./QueryState";
 import { PageToolbar } from "./PageShell";
 import { useWizard } from "./WizardProvider";
 import SortControl from "./SortControl";
+import FilterChipGroup, { filterChipClass } from "./FilterChipGroup";
 import ViewSwitcher from "./ViewSwitcher";
 import VirtualFeed from "./VirtualFeed";
 // Lazy: the in-app YouTube player (IFrame API) loads only when a video is first opened.
@@ -563,32 +564,35 @@ export default function Feed({
   const toolbar = (
     <div className="pb-3">
       <div className="flex items-center gap-1.5 gap-y-2 flex-wrap">
-        {SHOW_IDS.map((id) => (
+        <FilterChipGroup
-          <button
+          ariaLabel={t("feed.showLabel")}
-            key={id}
+          options={SHOW_IDS.map((id) => ({
-            data-testid={`feed-show-${id}`}
+            value: id,
-            onClick={() => setFilters({ ...filters, show: id })}
+            label: t("sidebar.show." + id),
-            aria-pressed={filters.show === id}
+            testId: `feed-show-${id}`,
-            className="pill text-xs px-3 py-1.5 rounded-full border"
+          }))}
-          >
+          value={filters.show}
-            {t("sidebar.show." + id)}
+          onChange={(show) => setFilters({ ...filters, show })}
-          </button>
+        />
-        ))}
         <span className="mx-1 h-5 w-px bg-border" aria-hidden="true" />
-        {CONTENT.map((c) => {
+        {/* Content-type toggles are MULTI-select (independent booleans) — same chip look via
-          const on = filters[c.key];
+            filterChipClass, but not a single-select group. */}
-          return (
+        <div className="flex flex-wrap gap-1.5" role="group" aria-label={t("feed.contentLabel")}>
-            <button
+          {CONTENT.map((c) => {
-              key={c.key}
+            const on = filters[c.key];
-              data-testid={`feed-content-${c.key}`}
+            return (
-              onClick={() => setFilters({ ...filters, [c.key]: !on })}
+              <button
-              aria-pressed={on}
+                key={c.key}
-              className="pill text-xs px-3 py-1.5 rounded-full border"
+                data-testid={`feed-content-${c.key}`}
-            >
+                onClick={() => setFilters({ ...filters, [c.key]: !on })}
-              {t(c.label)}
+                aria-pressed={on}
-            </button>
+                className={filterChipClass}
-          );
+              >
-        })}
+                {t(c.label)}
+              </button>
+            );
+          })}
+        </div>
         {/* The Source filter (organic / include-search / search-only) is a global-catalog concept —
             it selects how videos ENTERED the library. On a channel-scoped view we already show all
             of this one channel's videos (librarySource is pinned to "all"), so the selector would

frontend/src/components/FilterChipGroup.dom.test.tsx

@@ -0,0 +1,63 @@
+// @vitest-environment jsdom
+//
+// Rendering integration of the shared single-select FilterChipGroup. Labels are plain props; active
+// paint is CSS (`.pill[aria-pressed]`), so we assert the aria-pressed / onChange / testId contract.
+import { describe, it, expect, vi, afterEach } from "vitest";
+import { render, screen, fireEvent, cleanup } from "@testing-library/react";
+import FilterChipGroup, { filterChipClass } from "./FilterChipGroup";
+
+const OPTS = [
+  { value: "all", label: "All", testId: "chip-all" },
+  { value: "needsFull", label: "Needs full" },
+  { value: "fully", label: "Fully synced", count: 3 },
+] as const;
+
+afterEach(cleanup);
+
+describe("FilterChipGroup", () => {
+  it("renders one chip per option with labels", () => {
+    render(<FilterChipGroup options={OPTS} value="all" onChange={vi.fn()} ariaLabel="Sync" />);
+    expect(screen.getAllByRole("button").map((b) => b.textContent)).toEqual([
+      "All",
+      "Needs full",
+      "Fully synced3",
+    ]);
+  });
+
+  it("marks exactly the active chip aria-pressed", () => {
+    render(
+      <FilterChipGroup options={OPTS} value="needsFull" onChange={vi.fn()} ariaLabel="Sync" />,
+    );
+    expect(screen.getByRole("button", { name: "Needs full" }).getAttribute("aria-pressed")).toBe(
+      "true",
+    );
+    expect(screen.getByRole("button", { name: "All" }).getAttribute("aria-pressed")).toBe("false");
+  });
+
+  it("clicking a chip fires onChange with its value", () => {
+    const onChange = vi.fn();
+    render(<FilterChipGroup options={OPTS} value="all" onChange={onChange} ariaLabel="Sync" />);
+    fireEvent.click(screen.getByRole("button", { name: "Needs full" }));
+    expect(onChange).toHaveBeenCalledWith("needsFull");
+  });
+
+  it("re-clicking the active chip still fires onChange (caller decides toggle-off)", () => {
+    const onChange = vi.fn();
+    render(<FilterChipGroup options={OPTS} value="all" onChange={onChange} ariaLabel="Sync" />);
+    fireEvent.click(screen.getByRole("button", { name: "All" }));
+    expect(onChange).toHaveBeenCalledWith("all");
+  });
+
+  it("preserves per-option testId and exposes the group aria-label", () => {
+    render(
+      <FilterChipGroup options={OPTS} value="all" onChange={vi.fn()} ariaLabel="Sync state" />,
+    );
+    expect(screen.getByTestId("chip-all")).toBeTruthy();
+    expect(screen.getByRole("group", { name: "Sync state" })).toBeTruthy();
+  });
+
+  it("exports the canonical chip class for multi-select siblings to reuse", () => {
+    expect(filterChipClass).toContain("rounded-full");
+    expect(filterChipClass).toContain("pill");
+  });
+});

frontend/src/components/FilterChipGroup.tsx

@@ -0,0 +1,65 @@
+import { type ReactNode } from "react";
+
+// Canonical filter-chip geometry — the rounded-full "Filters bar" look used app-wide for a selectable
+// filter chip. Exported so single-select groups (this component) AND standalone/multi-select filter
+// chips (e.g. the feed content-type toggles) render identically from ONE source of truth. The active
+// paint comes entirely from the `.pill[aria-pressed="true"]` recipe (index.css) — carry no
+// bg/text/border-colour utilities here or a utility class would beat the pressed fill.
+export const filterChipClass =
+  "pill inline-flex items-center gap-1.5 text-xs px-2.5 py-1 rounded-full border shadow-xs active:translate-y-px";
+
+export interface FilterChipOption<T extends string> {
+  value: T;
+  label: string;
+  count?: number; // optional trailing count badge
+  icon?: ReactNode;
+  title?: string; // optional per-chip tooltip
+  testId?: string; // optional data-testid (preserve existing e2e hooks)
+}
+
+// A single-select row of filter chips (exactly one active), radio-like. For a multi-select chip row,
+// render plain buttons with `filterChipClass` instead — same look, different (independent) semantics.
+export default function FilterChipGroup<T extends string>({
+  options,
+  value,
+  onChange,
+  ariaLabel,
+  className = "flex flex-wrap gap-1.5",
+}: {
+  options: readonly FilterChipOption<T>[];
+  value: T;
+  onChange: (v: T) => void;
+  ariaLabel: string;
+  // Override the row wrapper (e.g. "contents" to dissolve it into a shared toolbar flex row).
+  className?: string;
+}) {
+  return (
+    <div className={className} role="group" aria-label={ariaLabel}>
+      {options.map((o) => {
+        const on = value === o.value;
+        return (
+          <button
+            key={o.value}
+            data-testid={o.testId}
+            onClick={() => onChange(o.value)}
+            title={o.title}
+            aria-pressed={on}
+            className={filterChipClass}
+          >
+            {o.icon}
+            <span>{o.label}</span>
+            {o.count != null && (
+              <span
+                className={`tabular-nums text-3xs leading-none px-1 py-0.5 rounded-full ${
+                  on ? "bg-accent-fg/20 text-accent-fg" : "bg-muted/15 text-muted"
+                }`}
+              >
+                {o.count}
+              </span>
+            )}
+          </button>
+        );
+      })}
+    </div>
+  );
+}

frontend/src/components/Sidebar.tsx

@@ -16,6 +16,7 @@ import SidePanel from "./SidePanel";
 import PanelGroups, { type PanelItem } from "./PanelGroups";
 import ChannelPicker from "./ChannelPicker";
 import SegmentedToggle from "./SegmentedToggle";
+import FilterChipGroup from "./FilterChipGroup";
 import { useFeedFilters, useFeedFiltersActions } from "./FeedFiltersProvider";
 import { useChannelsActions } from "./ChannelsProvider";
 import { useMe } from "../lib/useMe";
@@ -150,42 +151,47 @@ export default function Sidebar({
         return <SavedViewsWidget filters={filters} onApply={setFilters} />;
       case "channel":
         return <ChannelPicker filters={filters} setFilters={setFilters} />;
-      case "date":
+      case "date": {
+        // Single-select across the presets + Custom: a preset is active only when its maxAge matches
+        // and no custom range is open; otherwise Custom owns the selection (or none).
+        const activePresetDays = DATE_PRESETS.find(
+          (p) => filters.maxAgeDays === p.days && !customDates,
+        )?.days;
+        const dateKey =
+          customDates || filters.dateFrom || filters.dateTo
+            ? "custom"
+            : activePresetDays != null
+              ? String(activePresetDays)
+              : "";
         return (
           <>
-            <div className="flex flex-wrap gap-1.5">
+            <FilterChipGroup
-              {DATE_PRESETS.map((p) => {
+              ariaLabel={t("sidebar.datePresetLabel")}
-                const activePreset = filters.maxAgeDays === p.days && !customDates;
+              value={dateKey}
-                return (
+              options={[
-                  <button
+                ...DATE_PRESETS.map((p) => ({
-                    key={p.days}
+                  value: String(p.days),
-                    onClick={() =>
+                  label: t("sidebar.datePreset." + p.key),
-                      setFilters({
+                })),
-                        ...filters,
+                { value: "custom", label: t("sidebar.custom") },
-                        maxAgeDays: activePreset ? undefined : p.days,
+              ]}
-                        dateFrom: undefined,
+              onChange={(key) => {
-                        dateTo: undefined,
+                if (key === "custom") {
-                      })
-                    }
-                    aria-pressed={activePreset}
-                    className="pill text-xs px-2.5 py-1 rounded-full border shadow-xs active:translate-y-px"
-                  >
-                    {t("sidebar.datePreset." + p.key)}
-                  </button>
-                );
-              })}
-              <button
-                onClick={() => {
                   const next = !customDates;
                   setCustomDates(next);
                   if (next) setFilters({ ...filters, maxAgeDays: undefined });
-                }}
+                  return;
-                aria-pressed={!!(customDates || filters.dateFrom || filters.dateTo)}
+                }
-                className="pill text-xs px-2.5 py-1 rounded-full border shadow-xs active:translate-y-px"
+                const days = Number(key);
-              >
+                const activePreset = filters.maxAgeDays === days && !customDates;
-                {t("sidebar.custom")}
+                setFilters({
-              </button>
+                  ...filters,
-            </div>
+                  maxAgeDays: activePreset ? undefined : days,
+                  dateFrom: undefined,
+                  dateTo: undefined,
+                });
+              }}
+            />
 
             {(customDates || filters.dateFrom || filters.dateTo) && (
               <div className="flex flex-col gap-1.5 mt-2">
@@ -233,6 +239,7 @@ export default function Sidebar({
             )}
           </>
         );
+      }
       case "language": {
         const chips = visibleChips(languages);
         return (

frontend/src/i18n/locales/en/feed.json

@@ -20,6 +20,8 @@
   "videoCount_other": "{{formattedCount}} videos",
   "sortLabel": "Sort",
   "viewLabel": "View",
+  "showLabel": "Watch state",
+  "contentLabel": "Content types",
   "view": {
     "cards": "Large cards",
     "cardsSmall": "Small cards",

frontend/src/i18n/locales/en/sidebar.json

@@ -66,6 +66,7 @@
     "shorts": "Shorts",
     "live": "Live / Upcoming"
   },
+  "datePresetLabel": "Upload date",
   "datePreset": {
     "24h": "24h",
     "1week": "1 week",

frontend/src/i18n/locales/hu/feed.json

@@ -20,6 +20,8 @@
   "videoCount_other": "{{formattedCount}} videó",
   "sortLabel": "Rendezés",
   "viewLabel": "Nézet",
+  "showLabel": "Megtekintési állapot",
+  "contentLabel": "Tartalomtípusok",
   "view": {
     "cards": "Nagy kártya",
     "cardsSmall": "Kis kártya",

frontend/src/i18n/locales/hu/sidebar.json

@@ -66,6 +66,7 @@
     "shorts": "Shorts",
     "live": "Élő / Hamarosan"
   },
+  "datePresetLabel": "Feltöltés dátuma",
   "datePreset": {
     "24h": "24 óra",
     "1week": "1 hét",