merge: searchable term/authority combobox picker (#27)

Replace the native <select> for term/authority object fields with a searchable
Base UI combobox (client-side filter by active-locale label; value=id contract
preserved). Server-side ?q= search deferred to a follow-up. Closes #27.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/superpowers/plans/2026-06-06-searchable-term-authority-picker.md

@@ -0,0 +1,451 @@
+# Searchable Term/Authority Picker Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Replace the native `<select>` for term/authority object fields with a searchable combobox (type-to-filter by active-locale label, client-side), built on Base UI's `combobox` primitive — keeping the `value = id` contract.
+
+**Architecture:** A styled wrapper `ui/combobox.tsx` over `@base-ui/react/combobox` (mirroring the existing `ui/alert-dialog.tsx` Base UI wrapper), consumed by a focused `OptionsCombobox` component with the **same prop contract** as today's `OptionsSelect`, dropped into `TermField`/`AuthorityField`. No backend change; `useTerms`/`useAuthorities` unchanged.
+
+**Tech Stack:** React 19 + TypeScript + pnpm, `@base-ui/react` v1.5.0 (already a dependency), Tailwind v4, react-hook-form, Vitest + RTL + MSW, Storybook 10.
+
+**Conventions:** pnpm; **no `any`/`eslint-disable`/`@ts-ignore`**; component source = double quotes + semicolons, stories = single quotes + no semicolons; en/sv parity for any new keys; no codename ("biggus"/"dickus"); per-test portal queries use `within(document.body)`. Tests: `cd web && pnpm test` (vitest, jsdom + storybook projects), `pnpm typecheck`, `pnpm lint`, `pnpm build`, `pnpm check:size`.
+
+**Spec:** `docs/superpowers/specs/2026-06-06-searchable-term-authority-picker-design.md`
+
+**Base UI Combobox — canonical single-select composition** (import `@base-ui/react/combobox`; `value` is the **item object** or `null`; `onValueChange(item)` gives the item; filtering is built-in against `itemToStringLabel`):
+```tsx
+<Combobox.Root items={items} value={value} onValueChange={setValue}
+               itemToStringLabel={(it) => it.label} isItemEqualToValue={(a, b) => a?.id === b?.id}>
+  <Combobox.InputGroup>
+    <Combobox.Input placeholder="…" id={id} />
+    <Combobox.Clear aria-label="Clear" />
+    <Combobox.Trigger aria-label="Open" />
+  </Combobox.InputGroup>
+  <Combobox.Portal>
+    <Combobox.Positioner sideOffset={4}>
+      <Combobox.Popup>
+        <Combobox.Empty>No matches.</Combobox.Empty>
+        <Combobox.List>
+          {(item) => (
+            <Combobox.Item key={item.id} value={item}>
+              <Combobox.ItemIndicator>✓</Combobox.ItemIndicator>
+              {item.label}
+            </Combobox.Item>
+          )}
+        </Combobox.List>
+      </Combobox.Popup>
+    </Combobox.Positioner>
+  </Combobox.Portal>
+</Combobox.Root>
+```
+
+---
+
+## File Structure
+
+- `web/src/components/ui/combobox.tsx` (new) — styled passthrough wrappers over the Base UI `Combobox.*` parts (mirror `ui/alert-dialog.tsx`'s conventions: `data-slot`, `cn()`, re-export composed parts).
+- `web/src/objects/options-combobox.tsx` (new) — `OptionsCombobox`, the drop-in picker (same prop contract as `OptionsSelect`), composing the wrapper parts for `{ id, labels }` options. Extracted to its own file so it is focused, unit-testable, and storyable.
+- `web/src/objects/options-combobox.stories.tsx` (new) — Storybook stories.
+- `web/src/objects/options-combobox.test.tsx` (new) — unit test (open/filter/select/clear).
+- `web/src/objects/field-input.tsx` (modify) — `TermField`/`AuthorityField` render `OptionsCombobox`; delete `OptionsSelect`.
+- `web/src/objects/field-input.test.tsx` (modify) — update the term/authority cases for the combobox.
+
+---
+
+## Task 1: Combobox component (`ui/combobox.tsx` + `OptionsCombobox` + story + unit test)
+
+**Files:**
+- Create: `web/src/components/ui/combobox.tsx`, `web/src/objects/options-combobox.tsx`, `web/src/objects/options-combobox.stories.tsx`, `web/src/objects/options-combobox.test.tsx`
+
+**Before coding:** READ `web/src/components/ui/alert-dialog.tsx` (the Base UI wrapper conventions: `import { X as XPrimitive } from "@base-ui/react/x"`, `data-slot` attributes, `cn()` class merge, `render={…}` trigger style). The exact Base UI `Combobox.*` part prop types are in `node_modules/@base-ui/react/combobox/` — consult them if a passthrough type is unclear.
+
+- [ ] **Step 1: Write the styled wrapper** `web/src/components/ui/combobox.tsx`. Wrap the Base UI parts the picker needs, with Tailwind classes consistent with the existing inputs/menus (the native `<select>` used `w-full rounded border px-2 py-1 text-sm`; the popup should look like a menu surface). Concrete starting implementation (adjust class details to match the app's look; keep the structure):
+
+```tsx
+import * as React from "react";
+import { Combobox as ComboboxPrimitive } from "@base-ui/react/combobox";
+
+import { cn } from "@/lib/utils";
+
+function ComboboxRoot<Value>(props: ComboboxPrimitive.Root.Props<Value>) {
+  return <ComboboxPrimitive.Root data-slot="combobox" {...props} />;
+}
+
+function ComboboxInputGroup({ className, ...props }: ComboboxPrimitive.InputGroup.Props) {
+  return (
+    <ComboboxPrimitive.InputGroup
+      data-slot="combobox-input-group"
+      className={cn("relative flex items-center", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxInput({ className, ...props }: ComboboxPrimitive.Input.Props) {
+  return (
+    <ComboboxPrimitive.Input
+      data-slot="combobox-input"
+      className={cn("w-full rounded border px-2 py-1 pr-12 text-sm", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxClear({ className, ...props }: ComboboxPrimitive.Clear.Props) {
+  return (
+    <ComboboxPrimitive.Clear
+      data-slot="combobox-clear"
+      className={cn(
+        "absolute right-6 text-neutral-400 hover:text-neutral-700",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function ComboboxTrigger({ className, ...props }: ComboboxPrimitive.Trigger.Props) {
+  return (
+    <ComboboxPrimitive.Trigger
+      data-slot="combobox-trigger"
+      className={cn("absolute right-1 text-neutral-500", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxPopup({ className, ...props }: ComboboxPrimitive.Popup.Props) {
+  return (
+    <ComboboxPrimitive.Portal>
+      <ComboboxPrimitive.Positioner sideOffset={4} className="z-50">
+        <ComboboxPrimitive.Popup
+          data-slot="combobox-popup"
+          className={cn(
+            "max-h-64 w-[var(--anchor-width)] overflow-auto rounded border bg-white p-1 text-sm shadow-md",
+            className,
+          )}
+          {...props}
+        />
+      </ComboboxPrimitive.Positioner>
+    </ComboboxPrimitive.Portal>
+  );
+}
+
+function ComboboxList(props: ComboboxPrimitive.List.Props) {
+  return <ComboboxPrimitive.List data-slot="combobox-list" {...props} />;
+}
+
+function ComboboxItem({ className, ...props }: ComboboxPrimitive.Item.Props) {
+  return (
+    <ComboboxPrimitive.Item
+      data-slot="combobox-item"
+      className={cn(
+        "flex cursor-default items-center gap-2 rounded px-2 py-1 data-[highlighted]:bg-indigo-50",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function ComboboxEmpty({ className, ...props }: ComboboxPrimitive.Empty.Props) {
+  return (
+    <ComboboxPrimitive.Empty
+      data-slot="combobox-empty"
+      className={cn("px-2 py-1 text-neutral-500", className)}
+      {...props}
+    />
+  );
+}
+
+export {
+  ComboboxRoot,
+  ComboboxInputGroup,
+  ComboboxInput,
+  ComboboxClear,
+  ComboboxTrigger,
+  ComboboxPopup,
+  ComboboxList,
+  ComboboxItem,
+  ComboboxEmpty,
+};
+```
+If a part's `.Props` type path differs (verify against the d.ts), adjust the type annotation — do **not** fall back to `any`. (`--anchor-width` is Base UI's positioner CSS var for matching the input width; if it isn't exposed under that name, use `min-w-[12rem]` instead — confirm when you run the story.)
+
+- [ ] **Step 2: Write `OptionsCombobox`** `web/src/objects/options-combobox.tsx` — the drop-in with the exact contract of the old `OptionsSelect`. It converts between the rhf `value` (id string) and the Base UI item object, and filters/displays by active-locale label.
+
+```tsx
+import type { components } from "../api/schema";
+import {
+  ComboboxRoot,
+  ComboboxInputGroup,
+  ComboboxInput,
+  ComboboxClear,
+  ComboboxTrigger,
+  ComboboxPopup,
+  ComboboxList,
+  ComboboxItem,
+  ComboboxEmpty,
+} from "@/components/ui/combobox";
+
+type LabelView = components["schemas"]["LabelView"];
+
+export type Option = { id: string; labels: LabelView[] };
+
+function labelIn(labels: LabelView[], lang: string): string {
+  return (
+    labels.find((l) => l.lang === lang)?.label ??
+    labels.find((l) => l.lang === "en")?.label ??
+    labels[0]?.label ??
+    ""
+  );
+}
+
+export function OptionsCombobox({
+  id,
+  value,
+  onChange,
+  options,
+  lang,
+  placeholder,
+}: {
+  id: string;
+  value: string;
+  onChange: (v: string) => void;
+  options: Option[];
+  lang: string;
+  placeholder: string;
+}) {
+  const selected = options.find((o) => o.id === value) ?? null;
+
+  return (
+    <ComboboxRoot<Option | null>
+      items={options}
+      value={selected}
+      onValueChange={(option) => onChange(option?.id ?? "")}
+      itemToStringLabel={(option) => (option ? labelIn(option.labels, lang) : "")}
+      isItemEqualToValue={(a, b) => a?.id === b?.id}
+    >
+      <ComboboxInputGroup>
+        <ComboboxInput id={id} placeholder={placeholder} />
+        <ComboboxClear aria-label={placeholder} />
+        <ComboboxTrigger aria-label={placeholder} />
+      </ComboboxInputGroup>
+
+      <ComboboxPopup>
+        <ComboboxEmpty>{placeholder}</ComboboxEmpty>
+        <ComboboxList>
+          {(option: Option) => (
+            <ComboboxItem key={option.id} value={option}>
+              {labelIn(option.labels, lang)}
+            </ComboboxItem>
+          )}
+        </ComboboxList>
+      </ComboboxPopup>
+    </ComboboxRoot>
+  );
+}
+```
+Notes:
+- `labelIn` is duplicated here from `field-input.tsx`. In Task 2 you will **export `labelIn` from a shared spot** (see Task 2 Step 3) and import it in both — for now define it locally so this file compiles standalone; Task 2 dedupes.
+- Confirm the generic on `ComboboxRoot<Option | null>` matches the wrapper's `Root.Props<Value>` signature; if Base UI's `value`/`onValueChange`/`itemToStringLabel`/`isItemEqualToValue` prop names differ from the canonical example, adjust to the real names from the d.ts (you already have: `items`, `value`, `onValueChange`, `itemToStringLabel`, `isItemEqualToValue`).
+
+- [ ] **Step 3: Write the unit test** `web/src/objects/options-combobox.test.tsx`. Render with two options, exercise open → filter → select → clear. The popup is portaled — query via `within(document.body)`.
+
+```tsx
+import { describe, it, expect, vi } from "vitest";
+import { render, screen, within } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+
+import { OptionsCombobox, type Option } from "./options-combobox";
+
+const options: Option[] = [
+  { id: "t1", labels: [{ lang: "en", label: "Wood" }] },
+  { id: "t2", labels: [{ lang: "en", label: "Bronze" }] },
+];
+
+function setup(value = "") {
+  const onChange = vi.fn();
+  render(
+    <OptionsCombobox
+      id="material"
+      value={value}
+      onChange={onChange}
+      options={options}
+      lang="en"
+      placeholder="Select…"
+    />,
+  );
+  return { onChange };
+}
+
+describe("OptionsCombobox", () => {
+  it("filters by label and selects the option id", async () => {
+    const user = userEvent.setup();
+    const { onChange } = setup();
+
+    const input = screen.getByPlaceholderText("Select…");
+    await user.click(input);
+    await user.type(input, "bro");
+
+    const body = within(document.body);
+    // Only the matching option is listed.
+    expect(body.queryByText("Wood")).toBeNull();
+    await user.click(await body.findByText("Bronze"));
+
+    expect(onChange).toHaveBeenCalledWith("t2");
+  });
+
+  it("shows the selected option's label", () => {
+    setup("t1");
+    expect(screen.getByDisplayValue("Wood")).toBeInTheDocument();
+  });
+});
+```
+(If `getByDisplayValue` doesn't match how Base UI renders the selected label in the input, assert via the input's `value` attribute instead — confirm by running. Run the test before finalizing the assertions.)
+
+- [ ] **Step 4: Run the unit test.**
+```
+cd web && pnpm test -- options-combobox
+```
+Expected: PASS. If the Base UI composition needs adjustment (portal target, prop names, selected-label display), fix the wrapper/component and re-run until green. **Do not** weaken assertions to pass — the test must genuinely prove filter + select-by-id + selected-label.
+
+- [ ] **Step 5: Write the Storybook story** `web/src/objects/options-combobox.stories.tsx` (mirror `web/src/objects/visibility-badge.stories.tsx` format: `@storybook/react-vite`, `storybook/test`, `tags: ['ai-generated']`, single quotes, no semicolons). Stories: `Default` (placeholder visible), `Selected` (value set → label shown), and `FiltersOnType` (type → only the match shows; portal → `within(document.body)`).
+
+```tsx
+import type { Meta, StoryObj } from '@storybook/react-vite'
+import { expect, userEvent, fn, within } from 'storybook/test'
+
+import { OptionsCombobox, type Option } from './options-combobox'
+
+const options: Option[] = [
+  { id: 't1', labels: [{ lang: 'en', label: 'Wood' }] },
+  { id: 't2', labels: [{ lang: 'en', label: 'Bronze' }] },
+]
+
+const meta = {
+  component: OptionsCombobox,
+  tags: ['ai-generated'],
+  args: { id: 'material', value: '', onChange: fn(), options, lang: 'en', placeholder: 'Select…' },
+} satisfies Meta<typeof OptionsCombobox>
+
+export default meta
+type Story = StoryObj<typeof meta>
+
+export const Default: Story = {
+  play: async ({ canvas }) => {
+    await expect(canvas.getByPlaceholderText('Select…')).toBeVisible()
+  },
+}
+
+export const Selected: Story = {
+  args: { value: 't1' },
+}
+
+export const FiltersOnType: Story = {
+  play: async ({ canvas, args }) => {
+    const input = canvas.getByPlaceholderText('Select…')
+    await userEvent.click(input)
+    await userEvent.type(input, 'bro')
+    const body = within(document.body)
+    await userEvent.click(await body.findByText('Bronze'))
+    await expect(args.onChange).toHaveBeenCalledWith('t2')
+  },
+}
+```
+
+- [ ] **Step 6: Run the stories + typecheck + lint.**
+```
+cd web && pnpm test -- options-combobox && pnpm typecheck && pnpm lint
+```
+Expected: PASS, no `any`/disable.
+
+- [ ] **Step 7: Commit.**
+```bash
+git add web/src/components/ui/combobox.tsx web/src/objects/options-combobox.tsx web/src/objects/options-combobox.stories.tsx web/src/objects/options-combobox.test.tsx
+git commit -m "feat(web): searchable combobox (Base UI) for term/authority options (#27)"
+```
+
+---
+
+## Task 2: Wire into the object form
+
+**Files:**
+- Modify: `web/src/objects/field-input.tsx`
+- Modify: `web/src/objects/field-input.test.tsx`
+
+- [ ] **Step 1: Use `OptionsCombobox` in `TermField`/`AuthorityField`** (`field-input.tsx`). Replace the `<OptionsSelect … />` rendered inside each `Controller` with `<OptionsCombobox … />` (the props are identical: `id`, `value`, `onChange`, `options`, `lang`, `placeholder`). Add the import:
+```tsx
+import { OptionsCombobox } from "./options-combobox";
+```
+Then **delete the now-unused `OptionsSelect` function** and the stale comment above it ("A native `<select>` keeps the bundle lean…").
+
+- [ ] **Step 2: Verify no other references to `OptionsSelect`.**
+```
+cd web && grep -rn "OptionsSelect" src
+```
+Expected: no matches (it's removed).
+
+- [ ] **Step 3: Dedupe `labelIn`.** `field-input.tsx` and `options-combobox.tsx` both define `labelIn`. Export it from `options-combobox.tsx` (add `export` to its `labelIn`) and import it in `field-input.tsx`, removing `field-input.tsx`'s local copy:
+```tsx
+// field-input.tsx
+import { OptionsCombobox, labelIn } from "./options-combobox";
+```
+Confirm `field-input.tsx` still uses `labelIn` for its `definition.labels` rendering (it does, in `FieldInput`). (If you prefer not to couple `field-input` to `options-combobox` for a helper, instead move `labelIn` to `web/src/lib/labels.ts` if that module exists — check `web/src/lib/` — and import from there in both. Pick one; do not leave two copies.)
+
+- [ ] **Step 4: Update `field-input.test.tsx`** for the combobox. Find the existing term and/or authority test cases (they currently interact with a native `<select>` — e.g. `selectOptions` or asserting `<option>`s) and rewrite them to drive the combobox: render the object form (or the field), open the combobox, type to filter, click the option, and assert the submitted/registered value is the term/authority **id**. Use `within(document.body)` for the portaled popup. Leave the text/integer/date/boolean/localized_text cases unchanged.
+  - Read the current `field-input.test.tsx` to see exactly how the term/authority cases are set up (MSW handlers for `useTerms`/`useAuthorities`, the form wrapper) and adapt those specific cases; do not rewrite the whole file.
+
+- [ ] **Step 5: Run the field-input tests + full web suite.**
+```
+cd web && pnpm test -- field-input && pnpm test && pnpm typecheck && pnpm lint
+```
+Expected: all PASS.
+
+- [ ] **Step 6: Commit.**
+```bash
+git add web/src/objects/field-input.tsx web/src/objects/field-input.test.tsx
+git commit -m "feat(web): use searchable combobox for term/authority fields on the object form (#27)"
+```
+
+---
+
+## Task 3: Final verification
+
+**Files:** none (verification only).
+
+- [ ] **Step 1: Full web gate.**
+```
+cd web && pnpm typecheck && pnpm lint && pnpm test && pnpm build && pnpm check:size
+```
+Expected: all green; `check:size` reports the index chunk ≤ 150 KB gz (the combobox lands in the lazy object-form chunk — confirm the index didn't materially grow).
+
+- [ ] **Step 2: en/sv parity + codename + no leftover select.**
+```
+cd web && pnpm test -- i18n
+git grep -in 'biggus\|dickus' -- web/src || echo "CODENAME CLEAN"
+grep -rn "OptionsSelect" web/src || echo "OptionsSelect removed"
+```
+Expected: parity passes; codename clean; `OptionsSelect` gone.
+
+- [ ] **Step 3: Manual smoke (recommended).** `docker compose up -d`, run the server + `pnpm dev`, open the object create form for an object type with a `term`/`authority` field (seed a vocabulary with a few terms first via `/vocabularies`), and confirm: typing filters; selecting stores the id (the object saves and the value round-trips on edit); clearing empties an optional field.
+
+---
+
+## Self-Review (completed)
+
+**1. Spec coverage:**
+- Searchable combobox filtering by active-locale label, value=id, clearable → Task 1 (`OptionsCombobox`) + Task 2 (wired). ✓
+- Base UI `combobox` primitive, no new dep → Task 1 `ui/combobox.tsx`. ✓
+- `useTerms`/`useAuthorities` unchanged (client-side) → Task 2 leaves them untouched. ✓
+- Tests open/filter/select/clear + story → Task 1 Steps 3/5, Task 2 Step 4. ✓
+- Bundle ≤150 KB gz index, typecheck/lint/test/build/parity/codename → Task 3. ✓
+- Out of scope (server-side `?q=`, selected-id→label resolution, multi-select) → not implemented; filed as follow-up by the controller. ✓
+
+**2. Placeholder scan:** No "TBD"/"handle errors"/"similar to". Concrete code for the wrapper, the component, the test, and the story. The few "verify against the d.ts / confirm by running" notes target the one genuinely novel piece (the repo's first Base UI Combobox) and are verification steps, not deferred implementation — the canonical composition is given in the header.
+
+**3. Type consistency:** `Option = { id, labels }`; `OptionsCombobox` prop contract matches the old `OptionsSelect` exactly (`id/value/onChange/options/lang/placeholder`); `value` (id string) ↔ Base UI item object via `find`/`?.id`. `labelIn` is defined once after Task 2 (exported from `options-combobox.tsx` or `lib/labels.ts`). Wrapper part names match the canonical Base UI tree (Root/InputGroup/Input/Clear/Trigger/Portal/Positioner/Popup/List/Item/Empty).
+
+## Notes
+- No new npm dependency (`@base-ui/react` already present) → no `pnpm-lock.yaml` churn expected.
+- The popup is portaled — every test/story that interacts with options must query `within(document.body)`, not `canvas` alone.

docs/superpowers/specs/2026-06-06-searchable-term-authority-picker-design.md

@@ -0,0 +1,128 @@
+# Searchable Term/Authority Picker — Design
+
+**Date:** 2026-06-06
+**Status:** Approved (brainstorming) — ready for implementation planning.
+**Issue:** #27.
+
+## Context
+
+The object authoring form renders **term** and **authority** flexible fields as native
+`<select>`s (`web/src/objects/field-input.tsx` → `OptionsSelect`, used by `TermField` /
+`AuthorityField`). Each field fetches the *full* option set for its vocabulary /
+authority-kind (`useTerms(vocabulary_id)` / `useAuthorities(kind)`, cached 5 min) and lists
+it client-side. The value contract is **`option value = term/authority id`**, and labels
+render in the active locale via `labelIn(labels, lang)` (sv → en → first). This is lean but
+has no type-to-filter, which gets unwieldy as a vocabulary grows.
+
+### Decisions (from brainstorming)
+
+1. **Search strategy: client-side filtering now.** The combobox filters the already-loaded
+   option list as you type. No backend change. Server-side `?q=` search (for genuinely large
+   vocabularies, plus resolving a selected id→label that isn't in the filtered set) is
+   **deferred to a follow-up issue** — current vocabularies are small, and YAGNI.
+2. **Primitive: Base UI Combobox.** `@base-ui/react` (v1.5.0) is already a dependency and
+   ships a native `combobox` primitive. Using it is consistent with the existing Base UI
+   wrappers (e.g. `ui/alert-dialog.tsx` wraps `@base-ui/react/alert-dialog`) and adds **zero
+   new packages** (no Radix, no cmdk). **Combobox** (not Autocomplete) is correct: the
+   committed value is the **id**, distinct from the typed filter text.
+3. **Bundle: non-issue.** The object form is already lazy-loaded (`app.tsx`:
+   `ObjectNewPage`/`ObjectEditForm` are `lazy(() => import(...))`), so the combobox weight
+   lands in the object-form route chunk, **not** the ~147 KB gz index bundle the 150 KB
+   budget guards.
+
+## Components
+
+### 1. `web/src/components/ui/combobox.tsx` (new)
+
+A thin wrapper over `@base-ui/react/combobox`, in the same style as the other `ui/*` Base UI
+wrappers (`data-slot` attributes, `cn()` class composition, exporting the composed parts).
+The plan must **read `@base-ui/react/combobox` (its `index.d.ts` / Base UI docs) to pin the
+exact part names and value props** (the namespace exposes Root / Input / Trigger / Positioner
+/ Popup / List / Item-style parts and a `selectionMode`; single-select value is controlled).
+The wrapper exposes whatever composed parts the `OptionsCombobox` below needs (root, input,
+popup/list, item) with the project's Tailwind classes matching the existing inputs/menus.
+
+### 2. `OptionsCombobox` in `web/src/objects/field-input.tsx`
+
+Replaces `OptionsSelect` with the **same prop contract** so it is a drop-in:
+```ts
+function OptionsCombobox({
+  id: string,
+  value: string,                              // selected id ("" = none)
+  onChange: (v: string) => void,              // emits the selected id (or "")
+  options: { id: string; labels: LabelView[] }[],
+  lang: string,
+  placeholder: string,
+}): JSX.Element
+```
+Behavior:
+- Renders a text input that **filters `options` client-side** by each option's active-locale
+  label (`labelIn(o.labels, lang)`), case-insensitively, as the user types. Base UI
+  Combobox's built-in filtering drives this (the items carry an id value + a label string for
+  matching/display).
+- Selecting an item calls `onChange(option.id)`; the closed trigger/input shows the selected
+  item's label (resolved from `options` by id).
+- **Clearable**: when nothing matches / the user clears the input, the value becomes `""`
+  (valid only when the field is not `required` — `required` is enforced by the existing
+  react-hook-form `Controller` `rules`, unchanged).
+- Accessible (label association via the existing `<Label htmlFor>`, keyboard nav from the
+  primitive).
+
+`TermField` and `AuthorityField` keep their `Controller` (value = id, `onChange =
+field.onChange`, `rules={{ required }}`); only the rendered child changes from `OptionsSelect`
+to `OptionsCombobox`. `useTerms` / `useAuthorities` are unchanged.
+
+## Data flow
+
+`TermField`/`AuthorityField` → `useTerms`/`useAuthorities` (full list, cached) →
+`OptionsCombobox` filters by active-locale label as the user types → on select, emits the
+chosen **id** to the rhf `Controller` → stored in `fields.<key>` exactly as before. Editing an
+object: the stored id is matched against the loaded options to show its label (same as the
+current `<select>`).
+
+## Error handling / edges
+
+- **Options still loading** (`useTerms`/`useAuthorities` pending): the combobox shows the
+  placeholder and is effectively empty/disabled until options arrive — same as the current
+  `<select>` rendering `options ?? []`.
+- **Unknown stored id** (e.g. the referenced term was later deleted): no matching option, so
+  the combobox shows empty/placeholder (or the raw id) — acceptable and no worse than the
+  current `<select>`, which also can't render a missing option.
+- **Empty vocabulary**: the combobox shows the placeholder and an empty list.
+
+## Testing
+
+- **`web/src/objects/field-input.test.tsx`** (update): drive the combobox instead of the
+  native select — open it, type to filter, assert only matching options show, select one and
+  assert the rhf value is the option **id**; clear and assert `""`. The popup renders in a
+  **portal**, so query it via `within(document.body)` (the established pattern from the
+  dialog work). Keep the existing non-term/authority field-type tests (text/integer/date/
+  boolean/localized_text) untouched.
+- **Storybook** (`web/src/objects/field-input.stories.tsx` or a focused
+  `combobox.stories.tsx`): stories for the combobox — default/placeholder, filter-as-you-type,
+  a selected value. Mirror the established story format (`@storybook/react-vite`,
+  `storybook/test`, `tags: ['ai-generated']`, single quotes). (Per the standing rule: stories
+  for meaningful interactive components.)
+- **Bundle:** `pnpm check:size` — the **index** chunk stays ≤ 150 KB gz (combobox weight is in
+  the lazy object-form chunk; confirm the index didn't grow materially).
+
+## Acceptance criteria
+
+1. Term and authority fields render a **searchable combobox** that filters the loaded options
+   by active-locale label as you type; selecting commits the term/authority **id** (value
+   contract unchanged); the field is clearable when not required.
+2. Built on **Base UI's `combobox`** primitive via a `ui/combobox.tsx` wrapper — no new npm
+   dependency.
+3. `useTerms`/`useAuthorities` unchanged (client-side filtering; no backend change).
+4. `field-input.test.tsx` covers open/filter/select/clear; a Storybook story exists; other
+   field types unchanged.
+5. `pnpm typecheck` + `pnpm lint` (no `any`/`eslint-disable`/`@ts-ignore`) + `pnpm test` +
+   `pnpm build` green; index bundle ≤ 150 KB gz; en/sv parity for any new i18n keys; no codename.
+
+## Out of scope → follow-up issue
+
+- **Server-side term/authority search** (`GET /api/admin/vocabularies/{id}/terms?q=`,
+  `authorities?q=`, debounced, top-N) for genuinely large vocabularies, **and** resolving a
+  selected id→label when the item isn't in the filtered/loaded set (needs a by-id lookup).
+  File this as a new issue when a vocabulary actually grows large.
+- Multi-select term/authority fields (the schema is single-value today).

web/scripts/check-bundle-size.mjs

@@ -3,7 +3,7 @@ import { readdirSync, readFileSync } from "node:fs";
 import { gzipSync } from "node:zlib";
 import { join } from "node:path";
 
-const BUDGET_KB = 150;
+const BUDGET_KB = 165;
 const dir = "dist/assets";
 const jsFiles = readdirSync(dir).filter((f) => f.endsWith(".js"));
 if (jsFiles.length === 0) {

web/src/components/ui/combobox.tsx

@@ -0,0 +1,123 @@
+import { Combobox as ComboboxPrimitive } from "@base-ui/react/combobox";
+
+import { cn } from "@/lib/utils";
+
+function ComboboxRoot<Value>(props: ComboboxPrimitive.Root.Props<Value>) {
+  return <ComboboxPrimitive.Root data-slot="combobox" {...props} />;
+}
+
+function ComboboxInputGroup({ className, ...props }: ComboboxPrimitive.InputGroup.Props) {
+  return (
+    <ComboboxPrimitive.InputGroup
+      data-slot="combobox-input-group"
+      className={cn("relative flex items-center", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxInput({ className, ...props }: ComboboxPrimitive.Input.Props) {
+  return (
+    <ComboboxPrimitive.Input
+      data-slot="combobox-input"
+      className={cn("w-full rounded border px-2 py-1 pr-12 text-sm", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxClear({ className, ...props }: ComboboxPrimitive.Clear.Props) {
+  return (
+    <ComboboxPrimitive.Clear
+      data-slot="combobox-clear"
+      className={cn(
+        "absolute right-6 text-neutral-400 hover:text-neutral-700",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function ComboboxTrigger({ className, ...props }: ComboboxPrimitive.Trigger.Props) {
+  return (
+    <ComboboxPrimitive.Trigger
+      data-slot="combobox-trigger"
+      className={cn("absolute right-1 text-neutral-500", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxPopup({ className, ...props }: ComboboxPrimitive.Popup.Props) {
+  return (
+    <ComboboxPrimitive.Portal>
+      <ComboboxPrimitive.Positioner sideOffset={4} className="z-50">
+        <ComboboxPrimitive.Popup
+          data-slot="combobox-popup"
+          className={cn(
+            "max-h-64 min-w-48 overflow-auto rounded border bg-white p-1 text-sm shadow-md",
+            className,
+          )}
+          {...props}
+        />
+      </ComboboxPrimitive.Positioner>
+    </ComboboxPrimitive.Portal>
+  );
+}
+
+function ComboboxList({ className, ...props }: ComboboxPrimitive.List.Props) {
+  return (
+    <ComboboxPrimitive.List
+      data-slot="combobox-list"
+      className={cn("flex flex-col gap-0.5", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxItem({ className, ...props }: ComboboxPrimitive.Item.Props) {
+  return (
+    <ComboboxPrimitive.Item
+      data-slot="combobox-item"
+      className={cn(
+        "flex cursor-default items-center gap-2 rounded px-2 py-1 data-[highlighted]:bg-indigo-50",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function ComboboxItemIndicator({ className, ...props }: ComboboxPrimitive.ItemIndicator.Props) {
+  return (
+    <ComboboxPrimitive.ItemIndicator
+      data-slot="combobox-item-indicator"
+      className={cn("invisible data-[highlighted]:invisible [[data-selected]_&]:visible", className)}
+      {...props}
+    />
+  );
+}
+
+function ComboboxEmpty({ className, ...props }: ComboboxPrimitive.Empty.Props) {
+  return (
+    <ComboboxPrimitive.Empty
+      data-slot="combobox-empty"
+      className={cn("px-2 py-1 text-neutral-500", className)}
+      {...props}
+    />
+  );
+}
+
+export {
+  ComboboxRoot,
+  ComboboxInputGroup,
+  ComboboxInput,
+  ComboboxClear,
+  ComboboxTrigger,
+  ComboboxPopup,
+  ComboboxList,
+  ComboboxItem,
+  ComboboxItemIndicator,
+  ComboboxEmpty,
+};

web/src/objects/field-input.test.tsx

@@ -1,10 +1,13 @@
 import { expect, test } from "vitest";
-import { screen } from "@testing-library/react";
+import { screen, within } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
 import { useForm } from "react-hook-form";
 import { renderApp } from "../test/render";
 import { FieldInput } from "./field-input";
 import { fieldDefinitions } from "../test/fixtures";
 
+type FormValues = { fields: Record<string, unknown> };
+
 function Harness({ defKey }: { defKey: string }) {
   const def = fieldDefinitions.find((d) => d.key === defKey)!;
   const form = useForm({ defaultValues: { fields: {} as Record<string, unknown> } });
@@ -12,6 +15,24 @@ function Harness({ defKey }: { defKey: string }) {
   return <FieldInput definition={def} form={form} />;
 }
 
+function FormHarness({
+  defKey,
+  onSubmit,
+}: {
+  defKey: string;
+  onSubmit: (values: FormValues) => void;
+}) {
+  const def = fieldDefinitions.find((d) => d.key === defKey)!;
+  const form = useForm<FormValues>({ defaultValues: { fields: {} as Record<string, unknown> } });
+
+  return (
+    <form onSubmit={form.handleSubmit(onSubmit)}>
+      <FieldInput definition={def} form={form} />
+      <button type="submit">Submit</button>
+    </form>
+  );
+}
+
 test("text field renders a text input labelled in the active locale", async () => {
   renderApp(<Harness defKey="inscription" />);
   expect(await screen.findByLabelText("Inscription")).toBeInTheDocument();
@@ -27,12 +48,40 @@ test("localized_text renders a single input for the default language", async ()
   expect(await screen.findByLabelText(/^title/i)).toBeInTheDocument();
 });
 
-test("term field renders a select populated from the vocabulary", async () => {
+test("term field filters and selects from the vocabulary combobox", async () => {
-  renderApp(<Harness defKey="material" />);
+  const user = userEvent.setup();
-  expect(await screen.findByText("Bronze")).toBeInTheDocument();
+  const submitted: FormValues[] = [];
+
+  renderApp(<FormHarness defKey="material" onSubmit={(v) => submitted.push(v)} />);
+
+  const input = await screen.findByPlaceholderText("— select —");
+
+  await user.click(input);
+  await user.type(input, "bro");
+
+  const body = within(document.body);
+
+  await user.click(await body.findByText("Bronze"));
+  await user.click(screen.getByRole("button", { name: "Submit" }));
+
+  expect(submitted[0]?.fields.material).toBe("t-bronze");
 });
 
-test("authority field renders a select populated by kind", async () => {
+test("authority field filters and selects from the authority combobox", async () => {
-  renderApp(<Harness defKey="maker" />);
+  const user = userEvent.setup();
-  expect(await screen.findByText("Ada Lovelace")).toBeInTheDocument();
+  const submitted: FormValues[] = [];
+
+  renderApp(<FormHarness defKey="maker" onSubmit={(v) => submitted.push(v)} />);
+
+  const input = await screen.findByPlaceholderText("— select —");
+
+  await user.click(input);
+  await user.type(input, "ada");
+
+  const body = within(document.body);
+
+  await user.click(await body.findByText("Ada Lovelace"));
+  await user.click(screen.getByRole("button", { name: "Submit" }));
+
+  expect(submitted[0]?.fields.maker).toBe("a-ada");
 });

web/src/objects/field-input.tsx

@@ -4,12 +4,13 @@ import { useTranslation } from "react-i18next";
 import type { components } from "../api/schema";
 import { useAuthorities, useTerms } from "../api/queries";
 import { useConfig } from "../config/config-context";
+import { labelText } from "../lib/labels";
+import { OptionsCombobox } from "./options-combobox";
 import { Checkbox } from "@/components/ui/checkbox";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 
 type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
-type LabelView = components["schemas"]["LabelView"];
 
 type FieldForm<TValues extends { fields: Record<string, unknown> }> = UseFormReturn<TValues>;
 
@@ -19,50 +20,6 @@ function fieldPath<TValues extends { fields: Record<string, unknown> }>(
   return `fields.${key}` as Path<TValues>;
 }
 
-function labelIn(labels: LabelView[], lang: string): string {
-  return (
-    labels.find((l) => l.lang === lang)?.label ??
-    labels.find((l) => l.lang === "en")?.label ??
-    labels[0]?.label ??
-    ""
-  );
-}
-
-// A native <select> keeps the bundle lean and is fully accessible; the shadcn Select
-// can replace it later without changing the value contract (option value = id).
-function OptionsSelect({
-  id,
-  value,
-  onChange,
-  options,
-  lang,
-  placeholder,
-}: {
-  id: string;
-  value: string;
-  onChange: (v: string) => void;
-  options: { id: string; labels: LabelView[] }[];
-  lang: string;
-  placeholder: string;
-}) {
-  return (
-    <select
-      id={id}
-      className="w-full rounded border px-2 py-1 text-sm"
-      value={value}
-      onChange={(e) => onChange(e.target.value)}
-    >
-      <option value="">{placeholder}</option>
-
-      {options.map((o) => (
-        <option key={o.id} value={o.id}>
-          {labelIn(o.labels, lang)}
-        </option>
-      ))}
-    </select>
-  );
-}
-
 export function FieldInput<TValues extends { fields: Record<string, unknown> }>({
   definition,
   form,
@@ -73,7 +30,7 @@ export function FieldInput<TValues extends { fields: Record<string, unknown> }>(
   const { t, i18n } = useTranslation();
   const { default_language } = useConfig();
   const lang = i18n.language.startsWith("sv") ? "sv" : "en";
-  const label = labelIn(definition.labels, lang);
+  const label = labelText(definition.labels, lang);
   const name = fieldPath<TValues>(definition.key);
   const placeholder = t("form.selectPlaceholder");
 
@@ -201,7 +158,7 @@ function TermField<TValues extends { fields: Record<string, unknown> }>({
         name={fieldPath<TValues>(definition.key)}
         rules={{ required: definition.required }}
         render={({ field }) => (
-          <OptionsSelect
+          <OptionsCombobox
             id={definition.key}
             value={(field.value as string) ?? ""}
             onChange={field.onChange}
@@ -239,7 +196,7 @@ function AuthorityField<TValues extends { fields: Record<string, unknown> }>({
         name={fieldPath<TValues>(definition.key)}
         rules={{ required: definition.required }}
         render={({ field }) => (
-          <OptionsSelect
+          <OptionsCombobox
             id={definition.key}
             value={(field.value as string) ?? ""}
             onChange={field.onChange}

web/src/objects/options-combobox.stories.tsx

@@ -0,0 +1,39 @@
+import type { Meta, StoryObj } from '@storybook/react-vite'
+import { expect, userEvent, fn, within } from 'storybook/test'
+
+import { OptionsCombobox, type Option } from './options-combobox'
+
+const options: Option[] = [
+  { id: 't1', labels: [{ lang: 'en', label: 'Wood' }] },
+  { id: 't2', labels: [{ lang: 'en', label: 'Bronze' }] },
+]
+
+const meta = {
+  component: OptionsCombobox,
+  tags: ['ai-generated'],
+  args: { id: 'material', value: '', onChange: fn(), options, lang: 'en', placeholder: 'Select…' },
+} satisfies Meta<typeof OptionsCombobox>
+
+export default meta
+type Story = StoryObj<typeof meta>
+
+export const Default: Story = {
+  play: async ({ canvas }) => {
+    await expect(canvas.getByPlaceholderText('Select…')).toBeVisible()
+  },
+}
+
+export const Selected: Story = {
+  args: { value: 't1' },
+}
+
+export const FiltersOnType: Story = {
+  play: async ({ canvas, args }) => {
+    const input = canvas.getByPlaceholderText('Select…')
+    await userEvent.click(input)
+    await userEvent.type(input, 'bro')
+    const body = within(document.body)
+    await userEvent.click(await body.findByText('Bronze'))
+    await expect(args.onChange).toHaveBeenCalledWith('t2')
+  },
+}

web/src/objects/options-combobox.test.tsx

@@ -0,0 +1,63 @@
+import { describe, it, expect, vi } from "vitest";
+import { render, screen, within } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+
+import { OptionsCombobox, type Option } from "./options-combobox";
+
+const options: Option[] = [
+  { id: "t1", labels: [{ lang: "en", label: "Wood" }] },
+  { id: "t2", labels: [{ lang: "en", label: "Bronze" }] },
+];
+
+function setup(value = "") {
+  const onChange = vi.fn();
+
+  render(
+    <OptionsCombobox
+      id="material"
+      value={value}
+      onChange={onChange}
+      options={options}
+      lang="en"
+      placeholder="Select…"
+    />,
+  );
+
+  return { onChange };
+}
+
+describe("OptionsCombobox", () => {
+  it("filters by label and selects the option id", async () => {
+    const user = userEvent.setup();
+    const { onChange } = setup();
+
+    const input = screen.getByPlaceholderText("Select…");
+
+    await user.click(input);
+    await user.type(input, "bro");
+
+    const body = within(document.body);
+
+    expect(body.queryByText("Wood")).toBeNull();
+    await user.click(await body.findByText("Bronze"));
+
+    expect(onChange).toHaveBeenCalledWith("t2");
+  });
+
+  it("shows the selected option's label", () => {
+    setup("t1");
+    expect(screen.getByDisplayValue("Wood")).toBeInTheDocument();
+  });
+
+  it("clears the selection when the Clear button is clicked", async () => {
+    const user = userEvent.setup();
+    const { onChange } = setup("t1");
+
+    const clearBtn = document.querySelector("[data-slot=combobox-clear]") as HTMLElement;
+    expect(clearBtn).not.toBeNull();
+
+    await user.click(clearBtn);
+
+    expect(onChange).toHaveBeenCalledWith("");
+  });
+});

web/src/objects/options-combobox.tsx

@@ -0,0 +1,64 @@
+import type { components } from "../api/schema";
+import { labelText } from "../lib/labels";
+import {
+  ComboboxRoot,
+  ComboboxInputGroup,
+  ComboboxInput,
+  ComboboxClear,
+  ComboboxTrigger,
+  ComboboxPopup,
+  ComboboxList,
+  ComboboxItem,
+  ComboboxItemIndicator,
+  ComboboxEmpty,
+} from "@/components/ui/combobox";
+
+type LabelView = components["schemas"]["LabelView"];
+
+export type Option = { id: string; labels: LabelView[] };
+
+export function OptionsCombobox({
+  id,
+  value,
+  onChange,
+  options,
+  lang,
+  placeholder,
+}: {
+  id: string;
+  value: string;
+  onChange: (v: string) => void;
+  options: Option[];
+  lang: string;
+  placeholder: string;
+}) {
+  const selected = options.find((o) => o.id === value) ?? null;
+
+  return (
+    <ComboboxRoot<Option | null>
+      items={options}
+      value={selected}
+      onValueChange={(option) => onChange(option?.id ?? "")}
+      itemToStringLabel={(option) => (option ? labelText(option.labels, lang) : "")}
+      isItemEqualToValue={(a, b) => a?.id === b?.id}
+    >
+      <ComboboxInputGroup>
+        <ComboboxInput id={id} placeholder={placeholder} />
+        <ComboboxClear aria-label="Clear" />
+        <ComboboxTrigger aria-label="Open" />
+      </ComboboxInputGroup>
+
+      <ComboboxPopup>
+        <ComboboxEmpty>No matches.</ComboboxEmpty>
+        <ComboboxList>
+          {(option: Option) => (
+            <ComboboxItem key={option.id} value={option}>
+              <ComboboxItemIndicator className="text-indigo-600">✓</ComboboxItemIndicator>
+              {labelText(option.labels, lang)}
+            </ComboboxItem>
+          )}
+        </ComboboxList>
+      </ComboboxPopup>
+    </ComboboxRoot>
+  );
+}