feat(design): the field family, the dropdown trigger, native controls, the no-raw-input lint rule (E28 S3c)

- ui/Input, Textarea, InnerInput + fieldClass (A4): the >= 3:1 edge, a 2px accent
  focus edge, the danger edge for invalid, md/sm/xs/heading rungs, 1rem and 44 on touch
- ui/SelectTrigger (A5): SortControl, FilterSelect, the view switcher and the date
  filter on one trigger, a pill in a toolbar, r8 in a form
- ui/NativeControls (A6): Checkbox, CheckRow, Slider, ColorInput
- every raw input swept (~100 sites); inputCls retired; local/input-primitive
- useReturnFocus: an in-place editor hands the focus back to its trigger on
  Enter/Escape (the playlist and Plex title renames, the priority number);
  the Plex playlist rename gains Escape and an accessible name
- back to top: a round 48 FAB (owner decision); DESIGN.md A2 and the log

frontend/src/components/PlexCollectionEditor.tsx

@@ -10,6 +10,7 @@ import { Button } from "./ui/Button";
 import Modal from "./ui/Modal";
 import { useConfirm } from "./confirmContext";
 import { Pressable } from "./ui/Pressable";
+import { Input } from "./ui/Input";
 
 // Admin-only "manage this movie's collections" dialog (Collections P2). Lists the library's EDITABLE
 // collections with an in/out toggle (add/remove the movie, written back to Plex), plus a field to
@@ -144,12 +145,12 @@ export default function PlexCollectionEditor({
     <Modal title={t("plex.collEditor.title", { title: item.title })} onClose={onClose}>
       {/* Create new */}
       <div className="mb-3 flex gap-2">
-        <input
+        <Input
+          className="flex-1"
           value={newName}
           onChange={(e) => setNewName(e.target.value)}
           onKeyDown={(e) => e.key === "Enter" && createNew()}
           placeholder={t("plex.collEditor.newPlaceholder")}
-          className="glass-card min-w-0 flex-1 rounded-lg px-3 py-2 text-sm focus:outline-hidden focus:ring-2 focus:ring-accent/40"
         />
         <Button
           variant="glass"
@@ -165,11 +166,11 @@ export default function PlexCollectionEditor({
 
       {/* Filter */}
       {editable.length > 6 && (
-        <input
+        <Input
+          className="mb-2 w-full"
           value={q}
           onChange={(e) => setQ(e.target.value)}
           placeholder={t("plex.collEditor.search")}
-          className="glass-card mb-2 w-full rounded-lg px-3 py-1.5 text-sm focus:outline-hidden focus:ring-2 focus:ring-accent/40"
         />
       )}