Add the F favorite shortcut and the Ctrl+K tag finder

The command palette now searches e621 tags as you type (debounced
/tags.json suggestions with category chips and post counts), lets you
search a tag online, follow/unfollow it inline and open it on e621, and
remembers recent searches in localStorage. New navigation commands cover
Pools, Followed and Similar. On the online detail, F toggles the current
post's favorite.

ROADMAP.md

@@ -69,7 +69,9 @@ they land.
         blacklist-aware) and deleted-pool markers
   - [x] Pool detail: DText description, posts kept in pool order with chunked
         loading and in-library badges, blacklist reveal toggle, Follow button
-- [ ] `F` shortcut to favorite a post, tag finder in the Ctrl+K palette
+- [x] `F` shortcut to favorite a post (online detail), tag finder in the Ctrl+K
+      palette (e621 tag suggestions with follow toggles, recent searches, and
+      "search e621 for …")
 
 ## 3. Uploads & ingestion pipeline
 
@@ -116,7 +118,8 @@ Files now stage first and are resolved before entering the library.
 - [x] Profile pictures: staff Users page sets avatars from library J-IDs
       (self-service picker in Account still pending)
 - [ ] Profile extras (per-user browse preferences)
-- [ ] Command palette: tag finder, recent searches
+- [x] Command palette: tag finder, recent searches, navigation commands
+      (Ctrl+K / ⌘K, reachable from anywhere in the shell)
 
 ## 6. Infrastructure
 

frontend/src/components/CommandPalette.tsx

@@ -1,24 +1,65 @@
+import { useQuery } from "@tanstack/react-query";
 import {
   Copy,
+  ExternalLink,
   FolderOpen,
   Globe,
+  History,
+  Images,
+  Layers,
   LogIn,
   LogOut,
   Menu,
+  ScanSearch,
   Search,
   Settings,
+  Star,
   Trash2,
   Upload,
   Users,
   type LucideIcon,
 } from "lucide-react";
-import { useMemo, useState } from "react";
+import { useEffect, useMemo, useState } from "react";
 import { useNavigate } from "react-router-dom";
 
+import { TagChip } from "@/components/TagChip";
+import { Spinner } from "@/components/ui";
+import { TagFollowToggle } from "@/features/follows/TagFollowToggle";
 import { cn } from "@/lib/cn";
+import {
+  effectiveCredentials,
+  fetchTagSuggestions,
+  tagCategoryName,
+  type E621Tag,
+} from "@/lib/e621";
 import { useAuth } from "@/store/auth";
+import { useE621 } from "@/store/e621";
 import { useUi } from "@/store/ui";
 
+const RECENT_KEY = "j621.palette.recent-tags";
+const RECENT_LIMIT = 6;
+
+function readRecentTags(): string[] {
+  try {
+    const raw = window.localStorage.getItem(RECENT_KEY);
+    const parsed = raw ? (JSON.parse(raw) as unknown) : [];
+    if (!Array.isArray(parsed)) return [];
+    return parsed
+      .filter((value): value is string => typeof value === "string")
+      .slice(0, RECENT_LIMIT);
+  } catch {
+    return [];
+  }
+}
+
+function writeRecentTags(tags: string[]): void {
+  try {
+    window.localStorage.setItem(RECENT_KEY, JSON.stringify(tags));
+  } catch {
+    // Storage disabled: recents just won't persist.
+  }
+}
+
 interface Command {
   id: string;
   label: string;
@@ -27,6 +68,12 @@ interface Command {
   run: () => void;
 }
 
+type Row =
+  | { kind: "command"; key: string; command: Command }
+  | { kind: "tag"; key: string; tag: E621Tag }
+  | { kind: "recent"; key: string; tag: string }
+  | { kind: "search"; key: string; query: string };
+
 export function CommandPalette({
   open,
   onClose,
@@ -43,8 +90,26 @@ function CommandPaletteDialog({ onClose }: { onClose: () => void }) {
   const user = useAuth((state) => state.user);
   const logout = useAuth((state) => state.logout);
   const toggleSidebar = useUi((state) => state.toggleSidebar);
+  const credentials = useE621((state) => state.credentials);
+
   const [query, setQuery] = useState("");
+  const [debounced, setDebounced] = useState("");
   const [activeIndex, setActiveIndex] = useState(0);
+  const [recent, setRecent] = useState<string[]>(readRecentTags);
+
+  useEffect(() => {
+    const timer = window.setTimeout(() => setDebounced(query.trim()), 220);
+    return () => window.clearTimeout(timer);
+  }, [query]);
+
+  const tagsQuery = useQuery({
+    queryKey: ["palette-tags", debounced, credentials?.username ?? ""],
+    queryFn: ({ signal }) =>
+      fetchTagSuggestions(effectiveCredentials(credentials), debounced, signal),
+    enabled: debounced.length >= 2 && !debounced.includes(" "),
+    staleTime: 60_000,
+    retry: 0,
+  });
 
   const commands = useMemo<Command[]>(() => {
     const list: Command[] = [
@@ -54,6 +119,34 @@ function CommandPaletteDialog({ onClose }: { onClose: () => void }) {
         icon: FolderOpen,
         run: () => navigate("/"),
       },
+      {
+        id: "online",
+        label: "Go to Online browser",
+        icon: Globe,
+        run: () => navigate("/online"),
+      },
+      {
+        id: "pools",
+        label: "Go to Pools",
+        icon: Layers,
+        run: () => navigate("/pools"),
+      },
+      ...(user
+        ? [
+            {
+              id: "followed",
+              label: "Go to Followed",
+              icon: Star,
+              run: () => navigate("/followed"),
+            },
+            {
+              id: "similar",
+              label: "Check an image for similarity",
+              icon: ScanSearch,
+              run: () => navigate("/similar"),
+            },
+          ]
+        : []),
       ...(user?.can_upload
         ? [
             {
@@ -76,12 +169,6 @@ function CommandPaletteDialog({ onClose }: { onClose: () => void }) {
             },
           ]
         : []),
-      {
-        id: "online",
-        label: "Go to Online browser",
-        icon: Globe,
-        run: () => navigate("/online"),
-      },
       {
         id: "filters",
         label: "Toggle filters",
@@ -134,19 +221,124 @@ function CommandPaletteDialog({ onClose }: { onClose: () => void }) {
     return list;
   }, [navigate, toggleSidebar, user, logout]);
 
-  const filtered = useMemo(() => {
-    const needle = query.trim().toLowerCase();
-    return needle
-      ? commands.filter((command) =>
-          command.label.toLowerCase().includes(needle),
-        )
-      : commands;
-  }, [commands, query]);
+  const needle = query.trim().toLowerCase();
 
-  function runCommand(command: Command | undefined) {
-    if (!command) return;
+  const sections = useMemo(() => {
+    const searchRows: Row[] = needle
+      ? [{ kind: "search", key: "search", query: query.trim() }]
+      : [];
+    const tagRows: Row[] = (tagsQuery.data ?? []).map((tag) => ({
+      kind: "tag",
+      key: `tag-${tag.id}`,
+      tag,
+    }));
+    const recentRows: Row[] = !needle
+      ? recent.map((tag) => ({ kind: "recent", key: `recent-${tag}`, tag }))
+      : [];
+    const commandRows: Row[] = commands
+      .filter(
+        (command) => !needle || command.label.toLowerCase().includes(needle),
+      )
+      .map((command) => ({
+        kind: "command",
+        key: `cmd-${command.id}`,
+        command,
+      }));
+    return [
+      { title: "Actions", rows: searchRows },
+      { title: "Tags", rows: tagRows },
+      { title: "Recent searches", rows: recentRows },
+      { title: "Commands", rows: commandRows },
+    ].filter((section) => section.rows.length > 0);
+  }, [needle, query, recent, commands, tagsQuery.data]);
+
+  const flat = useMemo(() => sections.flatMap((section) => section.rows), [
+    sections,
+  ]);
+  const safeIndex = Math.min(activeIndex, Math.max(0, flat.length - 1));
+
+  function searchTag(value: string) {
+    const tag = value.trim();
+    if (!tag) return;
+    const next = [tag, ...recent.filter((entry) => entry !== tag)].slice(
+      0,
+      RECENT_LIMIT,
+    );
+    setRecent(next);
+    writeRecentTags(next);
     onClose();
-    command.run();
+    navigate(`/online?tags=${encodeURIComponent(tag)}`);
+  }
+
+  function runRow(row: Row | undefined) {
+    if (!row) return;
+    if (row.kind === "command") {
+      onClose();
+      row.command.run();
+      return;
+    }
+    if (row.kind === "tag") {
+      searchTag(row.tag.name);
+      return;
+    }
+    if (row.kind === "recent") {
+      searchTag(row.tag);
+      return;
+    }
+    searchTag(row.query);
+  }
+
+  function rowContent(row: Row) {
+    if (row.kind === "command") {
+      return (
+        <>
+          <row.command.icon className="h-4 w-4 shrink-0" />
+          <span className="flex-1 truncate">{row.command.label}</span>
+          {row.command.hint ? (
+            <span className="font-mono text-[11px] text-ctp-overlay0">
+              {row.command.hint}
+            </span>
+          ) : null}
+        </>
+      );
+    }
+    if (row.kind === "search") {
+      return (
+        <>
+          <Globe className="h-4 w-4 shrink-0" />
+          <span className="flex-1 truncate">
+            Search e621 for “{row.query}”
+          </span>
+        </>
+      );
+    }
+    if (row.kind === "recent") {
+      return (
+        <>
+          <History className="h-4 w-4 shrink-0" />
+          <span className="flex-1 truncate font-mono text-xs">{row.tag}</span>
+        </>
+      );
+    }
+    return (
+      <>
+        <TagChip tag={row.tag.name} category={tagCategoryName(row.tag.category)} />
+        <span className="ml-auto font-mono text-[11px] text-ctp-overlay0">
+          {row.tag.post_count.toLocaleString()} posts
+        </span>
+        <TagFollowToggle tag={row.tag.name} />
+        <a
+          href={`https://e621.net/posts?tags=${encodeURIComponent(row.tag.name)}`}
+          target="_blank"
+          rel="noreferrer"
+          title="Open on e621"
+          className="text-ctp-overlay0 transition hover:text-ctp-blue"
+          onClick={(event) => event.stopPropagation()}
+        >
+          <ExternalLink className="h-3.5 w-3.5" />
+        </a>
+      </>
+    );
   }
 
   return (
@@ -158,63 +350,83 @@ function CommandPaletteDialog({ onClose }: { onClose: () => void }) {
         className="w-full max-w-lg overflow-hidden rounded-lg border border-ctp-surface1 bg-ctp-surface0 shadow-[0_4px_12px_rgba(17,17,27,0.6)]"
         onClick={(event) => event.stopPropagation()}
       >
-        <input
-          autoFocus
-          value={query}
-          onChange={(event) => {
-            setQuery(event.target.value);
-            setActiveIndex(0);
-          }}
-          onKeyDown={(event) => {
-            if (event.key === "ArrowDown") {
-              event.preventDefault();
-              setActiveIndex((index) =>
-                Math.min(index + 1, filtered.length - 1),
-              );
-            } else if (event.key === "ArrowUp") {
-              event.preventDefault();
-              setActiveIndex((index) => Math.max(index - 1, 0));
-            } else if (event.key === "Enter") {
-              event.preventDefault();
-              runCommand(filtered[activeIndex]);
-            } else if (event.key === "Escape") {
-              onClose();
-            }
-          }}
-          placeholder="Type a command…"
-          className="w-full border-b border-ctp-surface1 bg-transparent px-4 py-3 font-mono text-sm text-ctp-text placeholder:text-ctp-overlay0 focus:outline-none"
-        />
-        <ul className="max-h-72 overflow-y-auto p-1.5">
-          {filtered.length === 0 ? (
-            <li className="px-3 py-6 text-center text-sm text-ctp-overlay0">
-              No matching commands
-            </li>
+        <div className="flex items-center gap-2 border-b border-ctp-surface1 px-4">
+          <Search className="h-4 w-4 shrink-0 text-ctp-overlay0" />
+          <input
+            autoFocus
+            value={query}
+            onChange={(event) => {
+              setQuery(event.target.value);
+              setActiveIndex(0);
+            }}
+            onKeyDown={(event) => {
+              if (event.key === "ArrowDown") {
+                event.preventDefault();
+                setActiveIndex((index) =>
+                  Math.min(index + 1, Math.max(0, flat.length - 1)),
+                );
+              } else if (event.key === "ArrowUp") {
+                event.preventDefault();
+                setActiveIndex((index) => Math.max(index - 1, 0));
+              } else if (event.key === "Enter") {
+                event.preventDefault();
+                runRow(flat[safeIndex]);
+              } else if (event.key === "Escape") {
+                onClose();
+              }
+            }}
+            placeholder="Search tags or run a command…"
+            className="w-full bg-transparent py-3 font-mono text-sm text-ctp-text placeholder:text-ctp-overlay0 focus:outline-none"
+          />
+          {tagsQuery.isFetching ? (
+            <Spinner className="h-3.5 w-3.5 shrink-0" />
+          ) : null}
+        </div>
+
+        <div className="max-h-80 overflow-y-auto p-1.5" role="listbox">
+          {flat.length === 0 ? (
+            <p className="px-3 py-6 text-center text-sm text-ctp-overlay0">
+              {needle ? "No matching commands or tags" : "Type to search"}
+            </p>
           ) : (
-            filtered.map((command, index) => (
-              <li key={command.id}>
-                <button
-                  type="button"
-                  onMouseEnter={() => setActiveIndex(index)}
-                  onClick={() => runCommand(command)}
-                  className={cn(
-                    "flex w-full items-center gap-3 rounded-md px-3 py-2 text-left text-sm transition",
-                    index === activeIndex
-                      ? "bg-ctp-surface1 text-ctp-text"
-                      : "text-ctp-subtext0",
-                  )}
-                >
-                  <command.icon className="h-4 w-4 shrink-0" />
-                  <span className="flex-1 truncate">{command.label}</span>
-                  {command.hint ? (
-                    <span className="font-mono text-[11px] text-ctp-overlay0">
-                      {command.hint}
-                    </span>
-                  ) : null}
-                </button>
-              </li>
+            sections.map((section) => (
+              <div key={section.title}>
+                <p className="px-3 pb-1 pt-2 text-[10px] font-medium uppercase tracking-wide text-ctp-overlay0">
+                  {section.title}
+                </p>
+                {section.rows.map((row) => {
+                  const index = flat.indexOf(row);
+                  const active = index === safeIndex;
+                  return (
+                    <div
+                      key={row.key}
+                      role="option"
+                      aria-selected={active}
+                      onMouseEnter={() => setActiveIndex(index)}
+                      onClick={() => runRow(row)}
+                      className={cn(
+                        "flex w-full cursor-pointer items-center gap-3 rounded-md px-3 py-2 text-left text-sm transition",
+                        active
+                          ? "bg-ctp-surface1 text-ctp-text"
+                          : "text-ctp-subtext0",
+                      )}
+                    >
+                      {rowContent(row)}
+                    </div>
+                  );
+                })}
+              </div>
             ))
           )}
-        </ul>
+        </div>
+
+        <div className="flex items-center gap-3 border-t border-ctp-surface1 px-4 py-2 text-[10px] text-ctp-overlay0">
+          <span className="flex items-center gap-1.5">
+            <Images className="h-3 w-3 shrink-0" /> Enter searches the
+            highlighted tag · + follows it
+          </span>
+          <span className="ml-auto font-mono">↑↓ · Esc</span>
+        </div>
       </div>
     </div>
   );

frontend/src/features/online/OnlineDetail.tsx

@@ -16,6 +16,7 @@ import { DetailShell } from "@/features/detail/DetailShell";
 import { api, errorMessage } from "@/lib/api";
 import { cn } from "@/lib/cn";
 import { renderDText } from "@/lib/dtext";
+import { isTypingTarget } from "@/lib/dom";
 import {
   e621ErrorMessage,
   effectiveCredentials,
@@ -118,6 +119,19 @@ export function OnlineDetail({ postId }: { postId: number }) {
 
   const [downloadTaskId, setDownloadTaskId] = useState<string | null>(null);
 
+  useEffect(() => {
+    function handleKeyDown(event: KeyboardEvent) {
+      if (event.ctrlKey || event.metaKey || event.altKey) return;
+      if (isTypingTarget(event.target)) return;
+      if (event.key.toLowerCase() !== "f") return;
+      if (!post || !credentials?.configured || favoriteMutation.isPending) return;
+      event.preventDefault();
+      favoriteMutation.mutate(!post.is_favorited);
+    }
+    window.addEventListener("keydown", handleKeyDown);
+    return () => window.removeEventListener("keydown", handleKeyDown);
+  }, [post, credentials, favoriteMutation]);
+
   const downloadMutation = useMutation({
     mutationFn: (target: NonNullable<typeof post>) =>
       api<DownloadTask>("/api/online/downloads/", {
@@ -234,7 +248,7 @@ export function OnlineDetail({ postId }: { postId: number }) {
               onClick={() => favoriteMutation.mutate(!post.is_favorited)}
               title={
                 credentials?.configured
-                  ? undefined
+                  ? "Toggle favorite (F)"
                   : "Add e621 credentials in Account to favorite posts"
               }
             >