feat(feed): per-category any/all tag match, in each combobox's popover footer

The tag 'Match: Any/All' toggle was a single GLOBAL setting that only ever
affected topics, shown as its own row under the Topic widget. Make it
per-category — language, topic, and 'your tags' each get their own independent
any/all — and move it into each filter combobox's popover footer (like
SortControl's direction segment), reclaiming the standalone Match row.

Backend: the feed query already groups selected tags by category; replace the
single tag_mode with per-category tag_mode_language/topic/other params and apply
the conjunctive (HAVING all) branch per category. Mirrored across filtered_query,
feed_summary.passes(), and the /facets drill-down exclusion (kept in lockstep;
equivalence test updated to tag_mode_topic). No schema change.

Frontend: FeedFilters.tagMode -> tagModes {language,topic,other} (pure leaf
lib/api/tagModes with a coerceTagModes migration for the legacy global value);
serialized to the API and the shareable URL per category (legacy ?tagmode=and
still resolves into the topic slot); saved-view blobs migrate on read. Combobox
gains an optional matchMode/onMatchModeChange footer segment, shown once 2+
values are picked; the three tag comboboxes wire it to their category.

Verified: backend feed tests green (12, incl. the count/facets equivalence net);
live, the footer appears at 2+ selections, toggles aria-pressed, serializes
tagmode_topic=and to the URL, and the request carries tag_mode_topic=and (200).
374 vitest, tsc, ruff, eslint (0 err).

frontend/src/components/ChannelPage.tsx

@@ -27,7 +27,7 @@ import { useFeedFilters } from "./FeedFiltersProvider";
 import { useConfirm } from "./ConfirmProvider";
 import { notify } from "../lib/notifications";
 import { notifyYouTubeActionError } from "../lib/youtubeErrors";
-import { api, type FeedFilters, type Me, type ChannelDetail } from "../lib/api";
+import { api, DEFAULT_TAG_MODES, type FeedFilters, type Me, type ChannelDetail } from "../lib/api";
 import type { FeedView } from "../lib/feedView";
 import { channelYouTubeUrl, formatViews } from "../lib/format";
 import { ChannelTagsControl } from "./ChannelTags";
@@ -231,7 +231,7 @@ export default function ChannelPage({
   // the explored, per-user-private videos show — the backend gates them to this explorer).
   const [filters, setFilters] = useState<FeedFilters>(() => ({
     tags: [],
-    tagMode: "or",
+    tagModes: DEFAULT_TAG_MODES,
     q: "",
     sort: "newest",
     scope: "all",

frontend/src/components/Combobox.tsx

@@ -55,6 +55,11 @@ export interface ComboboxProps {
   /** Chip/label text for a selected value whose option is not in the current (e.g. server-narrowed)
    *  list — the collection picker passes the stored title here so a reloaded filter still names itself. */
   selectedLabels?: Record<string, string>;
+  /** Optional "any/all" match segment in the popover footer (like SortControl's direction segment):
+   *  "or" = a match on ANY selected value, "and" = must match ALL. Provide BOTH to show it; it appears
+   *  only once 2+ values are selected (below that, any and all are the same). */
+  matchMode?: "or" | "and";
+  onMatchModeChange?: (mode: "or" | "and") => void;
 }
 
 export default function Combobox({
@@ -73,6 +78,8 @@ export default function Combobox({
   maxVisible = 50,
   renderOption,
   selectedLabels,
+  matchMode,
+  onMatchModeChange,
 }: ComboboxProps) {
   const { t } = useTranslation();
   const [open, setOpen] = useState(false);
@@ -282,6 +289,32 @@ export default function Combobox({
             </>
           )}
         </div>
+        {/* Any/all match segment (like SortControl's direction footer) — only meaningful, so only shown,
+            once 2+ values are picked. mousedown-preventDefault keeps the input focused so the list stays
+            open in the combobox's focus model. */}
+        {matchMode != null && onMatchModeChange && selected.length >= 2 && (
+          <div className="mt-1 flex items-center gap-2 border-t border-border px-1 pt-2">
+            <span className="text-2xs text-muted">{t("sidebar.match")}</span>
+            <div className="ml-auto flex gap-1">
+              {(["or", "and"] as const).map((m) => (
+                <button
+                  key={m}
+                  type="button"
+                  aria-pressed={matchMode === m}
+                  onMouseDown={(e) => e.preventDefault()}
+                  onClick={() => onMatchModeChange(m)}
+                  className={`rounded-md border px-2 py-0.5 text-2xs transition ${
+                    matchMode === m
+                      ? "border-accent bg-accent/15 text-accent"
+                      : "border-border text-muted hover:border-accent/50 hover:text-fg"
+                  }`}
+                >
+                  {t(m === "or" ? "sidebar.any" : "sidebar.all")}
+                </button>
+              ))}
+            </div>
+          </div>
+        )}
       </PopoverSurface>
     </div>
   );

frontend/src/components/FeedFiltersProvider.tsx

@@ -9,7 +9,7 @@ import {
 } from "react";
 import { qk } from "../lib/queryKeys";
 import { useQuery } from "@tanstack/react-query";
-import { api, getActiveAccount, type FeedFilters } from "../lib/api";
+import { api, getActiveAccount, DEFAULT_TAG_MODES, type FeedFilters } from "../lib/api";
 import { filterParamUpdates, hasFilterParams, paramsToFilters } from "../lib/urlState";
 import { useUrlMirror } from "../lib/useUrlMirror";
 import { accountKey, LS, readJSON, readMerged, writeJSON } from "../lib/storage";
@@ -32,7 +32,7 @@ import { useNavigation } from "./NavigationProvider";
 
 const DEFAULT_FILTERS: FeedFilters = {
   tags: [],
-  tagMode: "or",
+  tagModes: DEFAULT_TAG_MODES,
   channelIds: [],
   q: "",
   sort: "newest",

frontend/src/components/SavedViewsWidget.tsx

@@ -18,7 +18,13 @@ import {
   verticalListSortingStrategy,
 } from "@dnd-kit/sortable";
 import { CSS } from "@dnd-kit/utilities";
-import { api, getActiveAccount, type FeedFilters, type SavedView } from "../lib/api";
+import {
+  api,
+  getActiveAccount,
+  coerceTagModes,
+  type FeedFilters,
+  type SavedView,
+} from "../lib/api";
 import { filtersToParams } from "../lib/urlState";
 import { notifyActionError } from "../lib/actionErrors";
 import { accountKey, LS, writeJSON } from "../lib/storage";
@@ -37,6 +43,8 @@ const asFilters = (raw: FeedFilters): FeedFilters => ({
   ...raw,
   tags: raw.tags ?? [],
   channelIds: raw.channelIds ?? [],
+  // Migrate the legacy global `tagMode` (older blobs) into the per-category shape.
+  tagModes: coerceTagModes(raw),
 });
 
 function syncDefaultMirror(views: SavedView[]): void {

frontend/src/components/Sidebar.tsx

@@ -3,7 +3,7 @@ import { useTranslation } from "react-i18next";
 import { keepPreviousData, useQuery } from "@tanstack/react-query";
 import { qk } from "../lib/queryKeys";
 import { Pencil, SlidersHorizontal } from "lucide-react";
-import { api, type FeedFilters, type Tag } from "../lib/api";
+import { api, type FeedFilters, type Tag, type TagCategory } from "../lib/api";
 import { defaultLayout, type PanelLayout } from "../lib/panelLayout";
 import { useDebounced } from "../lib/useDebounced";
 import { clearedFilters, useActiveFilters } from "../lib/useActiveFilters";
@@ -14,7 +14,6 @@ import FilterRail from "./FilterRail";
 import { type PanelItem } from "./PanelGroups";
 import { type MediaSourceKind } from "../lib/mediaSource";
 import ChannelPicker from "./ChannelPicker";
-import SegmentedToggle from "./SegmentedToggle";
 import FilterChipGroup from "./FilterChipGroup";
 import Combobox, { type ComboboxOption } from "./Combobox";
 import { useFeedFilters, useFeedFiltersActions } from "./FeedFiltersProvider";
@@ -97,6 +96,9 @@ export default function Sidebar({
       tags: [...filters.tags.filter((id) => !inList.has(id)), ...next.map(Number)],
     });
   }
+  // Each tag category (language/topic/other) has its OWN any/all match, set from its combobox footer.
+  const setTagMode = (category: TagCategory, mode: "or" | "and") =>
+    setFilters({ ...filters, tagModes: { ...filters.tagModes, [category]: mode } });
 
   // The badge counts exactly what the chip row above the feed shows — same list, so they can't
   // disagree about what's applied.
@@ -200,31 +202,22 @@ export default function Sidebar({
             selected={selectedIn(languages)}
             onChange={(next) => setTagSelection(languages, next)}
             emptyText={t("sidebar.noMatchingTags")}
+            matchMode={filters.tagModes.language}
+            onMatchModeChange={(m) => setTagMode("language", m)}
           />
         );
       }
       case "topic": {
         return (
-          <div className="flex flex-col gap-2">
-            <SegmentedToggle
-              label={t("sidebar.match")}
-              title={t("sidebar.tagModeTooltip")}
-              ariaLabel={t("sidebar.match")}
-              options={[
-                { value: "or", label: t("sidebar.any") },
-                { value: "and", label: t("sidebar.all") },
-              ]}
-              value={filters.tagMode}
-              onChange={(tagMode) => setFilters({ ...filters, tagMode })}
-            />
-            <Combobox
-              label={t("sidebar.widget.topic")}
-              options={visibleChips(topics).map(tagOption)}
-              selected={selectedIn(topics)}
-              onChange={(next) => setTagSelection(topics, next)}
-              emptyText={t("sidebar.noMatchingTags")}
-            />
-          </div>
+          <Combobox
+            label={t("sidebar.widget.topic")}
+            options={visibleChips(topics).map(tagOption)}
+            selected={selectedIn(topics)}
+            onChange={(next) => setTagSelection(topics, next)}
+            emptyText={t("sidebar.noMatchingTags")}
+            matchMode={filters.tagModes.topic}
+            onMatchModeChange={(m) => setTagMode("topic", m)}
+          />
         );
       }
       case "tags": {
@@ -236,6 +229,8 @@ export default function Sidebar({
               selected={selectedIn(userTags)}
               onChange={(next) => setTagSelection(userTags, next)}
               emptyText={t("sidebar.noMatchingTags")}
+              matchMode={filters.tagModes.other}
+              onMatchModeChange={(m) => setTagMode("other", m)}
             />
             <button
               onClick={() => setTagManagerOpen(true)}