feat(feed): compress the toolbar chip groups into labeled FilterSelect dropdowns

Adds a reusable FilterSelect: a "Label: value ▾" pill that opens a listbox (a checkmark
row for single-select, a checkbox row for multi), on the AnchoredPopover platform. It
replaces the two feed-toolbar chip walls:
  - Watch state (single-select, default All) — picking a row replaces + closes.
  - Content types (multi-select, default Normal; requireOne keeps at least one on) — rows
    toggle and the panel stays open.
The trigger summarises multi picks as "First +N". The component is source-agnostic, meant
for reuse anywhere a small known option set currently renders as a chip group.

FilterSelect takes a `testId` → the trigger gets it, each option gets `${testId}-${value}`,
so the feed/channel E2Es keep stable selectors. They now open the dropdown and assert the
option's aria-selected instead of the old inline aria-pressed chips (new expectContentType/
toggleContentType helpers).

frontend/src/components/Feed.tsx

@@ -40,7 +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 FilterSelect from "./FilterSelect";
 import ViewSwitcher from "./ViewSwitcher";
 import VirtualFeed from "./VirtualFeed";
 // Lazy: the in-app YouTube player (IFrame API) loads only when a video is first opened.
@@ -570,35 +570,27 @@ export default function Feed({
   const toolbar = (
     <div className="pb-3">
       <div className="flex items-center gap-1.5 gap-y-2 flex-wrap">
-        <FilterChipGroup
-          ariaLabel={t("feed.showLabel")}
-          options={SHOW_IDS.map((id) => ({
-            value: id,
-            label: t("sidebar.show." + id),
-            testId: `feed-show-${id}`,
-          }))}
-          value={filters.show}
-          onChange={(show) => setFilters({ ...filters, show })}
+        {/* Watch state is single-select (always exactly one); content types are an independent
+            multi-select. Both compress to one labeled dropdown pill via FilterSelect. */}
+        <FilterSelect
+          label={t("feed.showLabel")}
+          testId="feed-show"
+          options={SHOW_IDS.map((id) => ({ value: id, label: t("sidebar.show." + id) }))}
+          selected={[filters.show]}
+          onChange={(next) => setFilters({ ...filters, show: next[0] as FeedFilters["show"] })}
+        />
+        <FilterSelect
+          label={t("feed.contentLabel")}
+          testId="feed-content"
+          multiple
+          options={CONTENT.map((c) => ({ value: c.key, label: t(c.label) }))}
+          selected={CONTENT.filter((c) => filters[c.key]).map((c) => c.key)}
+          onChange={(next) => {
+            const patch = { ...filters };
+            for (const c of CONTENT) patch[c.key] = next.includes(c.key);
+            setFilters(patch);
+          }}
         />
-        <span className="mx-1 h-5 w-px bg-border" aria-hidden="true" />
-        {/* Content-type toggles are MULTI-select (independent booleans) — same chip look via
-            filterChipClass, but not a single-select group. */}
-        <div className="flex flex-wrap gap-1.5" role="group" aria-label={t("feed.contentLabel")}>
-          {CONTENT.map((c) => {
-            const on = filters[c.key];
-            return (
-              <button
-                key={c.key}
-                data-testid={`feed-content-${c.key}`}
-                onClick={() => setFilters({ ...filters, [c.key]: !on })}
-                aria-pressed={on}
-                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/FilterSelect.dom.test.tsx

@@ -0,0 +1,92 @@
+// @vitest-environment jsdom
+//
+// Contract of the labeled-pill FilterSelect. Labels are plain props (no i18n). Built on the floating-ui
+// AnchoredPopover platform, so we stub the two observers autoUpdate wires and wrap in a FloatingTree.
+// floating-ui never positions in jsdom → the surface stays visibility:hidden, so option/listbox role
+// queries pass `{ hidden: true }`.
+import { describe, it, expect, vi, afterEach, beforeAll } from "vitest";
+import { render, screen, fireEvent, cleanup } from "@testing-library/react";
+import { FloatingTree } from "@floating-ui/react";
+import FilterSelect, { type FilterSelectOption } from "./FilterSelect";
+
+beforeAll(() => {
+  class Stub {
+    observe() {}
+    unobserve() {}
+    disconnect() {}
+    takeRecords() {
+      return [];
+    }
+  }
+  globalThis.ResizeObserver ??= Stub as unknown as typeof ResizeObserver;
+  globalThis.IntersectionObserver ??= Stub as unknown as typeof IntersectionObserver;
+});
+
+afterEach(cleanup);
+
+const STATUS: FilterSelectOption[] = [
+  { value: "all", label: "All" },
+  { value: "new", label: "New" },
+];
+const TYPES: FilterSelectOption[] = [
+  { value: "n", label: "Normal" },
+  { value: "s", label: "Shorts" },
+];
+const tree = (ui: React.ReactNode) => render(<FloatingTree>{ui}</FloatingTree>);
+
+describe("FilterSelect", () => {
+  it("renders a labeled trigger `Label: value` and keeps options unmounted until opened", () => {
+    tree(<FilterSelect label="Status" options={STATUS} selected={["all"]} onChange={vi.fn()} />);
+    const trigger = screen.getByRole("button", { name: "Status" });
+    expect(trigger.textContent).toContain("Status:");
+    expect(trigger.textContent).toContain("All");
+    expect(screen.queryByRole("option", { hidden: true })).toBeNull();
+  });
+
+  it("single: picking a row replaces the selection and closes", () => {
+    const onChange = vi.fn();
+    tree(<FilterSelect label="Status" options={STATUS} selected={["all"]} onChange={onChange} />);
+    fireEvent.click(screen.getByRole("button", { name: "Status" }));
+    expect(screen.getAllByRole("option", { hidden: true }).map((o) => o.textContent)).toEqual([
+      "All",
+      "New",
+    ]);
+    fireEvent.click(screen.getAllByRole("option", { hidden: true })[1]!); // New
+    expect(onChange).toHaveBeenCalledWith(["new"]);
+    expect(screen.queryByRole("option", { hidden: true })).toBeNull();
+  });
+
+  it("multiple: toggling a row adds it and keeps the panel open", () => {
+    const onChange = vi.fn();
+    tree(
+      <FilterSelect label="Type" multiple options={TYPES} selected={["n"]} onChange={onChange} />,
+    );
+    fireEvent.click(screen.getByRole("button", { name: "Type" }));
+    fireEvent.click(screen.getAllByRole("option", { hidden: true })[1]!); // Shorts
+    expect(onChange).toHaveBeenCalledWith(["n", "s"]);
+    expect(screen.queryAllByRole("option", { hidden: true }).length).toBeGreaterThan(0); // still open
+  });
+
+  it("multiple + requireOne: the last remaining selection can't be turned off", () => {
+    const onChange = vi.fn();
+    tree(
+      <FilterSelect label="Type" multiple options={TYPES} selected={["n"]} onChange={onChange} />,
+    );
+    fireEvent.click(screen.getByRole("button", { name: "Type" }));
+    fireEvent.click(screen.getAllByRole("option", { hidden: true })[0]!); // Normal — the only one selected
+    expect(onChange).not.toHaveBeenCalled();
+  });
+
+  it("multiple: the trigger summarises extra picks as `First +N`", () => {
+    tree(
+      <FilterSelect
+        label="Type"
+        multiple
+        options={TYPES}
+        selected={["n", "s"]}
+        onChange={vi.fn()}
+      />,
+    );
+    expect(screen.getByRole("button", { name: "Type" }).textContent).toContain("Normal +1");
+  });
+});

frontend/src/components/FilterSelect.tsx

@@ -0,0 +1,135 @@
+import { useState } from "react";
+import { ChevronDown, Check } from "lucide-react";
+import { PopoverItem, PopoverSurface, useAnchoredPopover } from "./AnchoredPopover";
+
+// A compact "labeled pill → dropdown" filter control: the trigger reads `Label: value ▾`, and clicking
+// it opens a listbox of options (facet counts optional). It replaces a wall of individual toolbar chips
+// with one pill per filter group, in two flavours:
+//   - single  (default): picking a row replaces the choice and closes — always exactly one active.
+//   - multiple: rows toggle independently and the panel stays open; `requireOne` blocks clearing the last.
+// Built on the same AnchoredPopover platform as ActionMenu/Combobox (arrows/typeahead/Escape/anchor-flip);
+// reusable anywhere a small, known set of options currently renders as a chip group. See FilterSelect.dom.test.
+
+export interface FilterSelectOption {
+  value: string;
+  label: string;
+  /** A facet count shown at the row's end. */
+  count?: number;
+  disabled?: boolean;
+}
+
+export interface FilterSelectProps {
+  /** Visible group name shown as the trigger prefix (`Label: value`) and the accessible name. */
+  label: string;
+  options: readonly FilterSelectOption[];
+  selected: string[];
+  onChange: (next: string[]) => void;
+  /** Toggle a subset (default false = pick exactly one). */
+  multiple?: boolean;
+  /** Multi only: keep at least one selected — the last active row can't be turned off. Default true. */
+  requireOne?: boolean;
+  /** Test hook: the trigger gets `data-testid={testId}`; each option gets `${testId}-${value}`. */
+  testId?: string;
+}
+
+export default function FilterSelect({
+  label,
+  options,
+  selected,
+  onChange,
+  multiple = false,
+  requireOne = true,
+  testId,
+}: FilterSelectProps) {
+  const [open, setOpen] = useState(false);
+  const pop = useAnchoredPopover({
+    open,
+    onOpenChange: setOpen,
+    mode: "listbox",
+    placement: "bottom-start",
+  });
+
+  const labelOf = (v: string) => options.find((o) => o.value === v)?.label ?? v;
+  // Summarise the trigger value. Multi lists the first chosen (in options order, so it's stable) + "+N".
+  const chosen = options.filter((o) => selected.includes(o.value));
+  const first = chosen[0];
+  const summary = multiple
+    ? first
+      ? `${first.label}${chosen.length > 1 ? ` +${chosen.length - 1}` : ""}`
+      : "—"
+    : labelOf(selected[0] ?? options[0]?.value ?? "");
+
+  const commit = (value: string) => {
+    if (!multiple) {
+      onChange([value]);
+      setOpen(false);
+      return;
+    }
+    const has = selected.includes(value);
+    if (has) {
+      if (requireOne && selected.length === 1) return; // don't let the last one go
+      onChange(selected.filter((x) => x !== value));
+    } else {
+      onChange([...selected, value]);
+    }
+  };
+
+  return (
+    <>
+      <button
+        type="button"
+        ref={pop.refs.setReference}
+        {...pop.getReferenceProps()}
+        data-testid={testId}
+        aria-label={label}
+        className={`glass-card glass-hover inline-flex items-center gap-1.5 rounded-full border px-3 py-1 text-xs transition ${
+          open ? "border-accent" : "border-border"
+        }`}
+      >
+        <span className="text-muted">{label}:</span>
+        <span className="text-fg">{summary}</span>
+        <ChevronDown className="h-3.5 w-3.5 shrink-0 text-muted" aria-hidden="true" />
+      </button>
+
+      <PopoverSurface
+        popover={pop}
+        ariaLabel={label}
+        className="glass-menu min-w-52 rounded-xl p-1.5 shadow-lg animate-[popIn_0.16s_ease]"
+      >
+        {options.map((o) => {
+          const on = selected.includes(o.value);
+          return (
+            <PopoverItem
+              key={o.value}
+              role="option"
+              selected={on}
+              disabled={o.disabled}
+              onSelect={() => commit(o.value)}
+              label={o.label}
+              data-testid={testId ? `${testId}-${o.value}` : undefined}
+              className={`flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-left text-sm transition ${
+                on ? "text-fg" : "text-muted"
+              }`}
+            >
+              {multiple ? (
+                <span
+                  className={`flex h-3.5 w-3.5 shrink-0 items-center justify-center rounded border ${
+                    on ? "border-accent bg-accent text-accent-fg" : "border-border"
+                  }`}
+                >
+                  {on && <Check className="h-2.5 w-2.5" />}
+                </span>
+              ) : (
+                <Check className={`h-3.5 w-3.5 shrink-0 ${on ? "text-accent" : "opacity-0"}`} />
+              )}
+              <span className="flex-1 truncate">{o.label}</span>
+              {o.count != null && (
+                <span className="shrink-0 text-2xs tabular-nums text-muted">{o.count}</span>
+              )}
+            </PopoverItem>
+          );
+        })}
+      </PopoverSurface>
+    </>
+  );
+}