feat(tickets): persistance des filtres tickets entre redémarrages (#29)

Introduit le port UiPreferencesGateway et son adapter uiPreferences,
avec le module ticketFilterPersistence qui sauvegarde/restaure les
filtres (recherche, statut, sprint, agents) via useTickets,
useTicketSearch et useProjectAgents. Couvert par tests unitaires et
un test d'intégration.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/adapters/index.ts

@@ -30,6 +30,7 @@ import { TauriWorkStateGateway } from "./workState";
 import { TauriConversationGateway } from "./conversation";
 import { TauriTicketGateway } from "./ticket";
 import { TauriWindowGateway } from "./window";
+import { LocalStorageUiPreferencesGateway } from "./uiPreferences";
 
 function notImplemented(what: string): never {
   const err: GatewayError = {
@@ -67,6 +68,7 @@ export function createTauriGateways(): Gateways {
     conversation: new TauriConversationGateway(),
     ticket: new TauriTicketGateway(),
     window: new TauriWindowGateway(),
+    uiPreferences: new LocalStorageUiPreferencesGateway(),
   };
 }
 
@@ -89,4 +91,5 @@ export {
   TauriConversationGateway,
   TauriTicketGateway,
   TauriWindowGateway,
+  LocalStorageUiPreferencesGateway,
 };

frontend/src/adapters/mock/index.ts

@@ -88,6 +88,7 @@ import type {
   TicketListQuery,
   CreateTicketInput,
   UpdateTicketInput,
+  UiPreferencesGateway,
   ViewWindowClosed,
   WindowGateway,
   WorkStateGateway,
@@ -2529,6 +2530,38 @@ export class MockTicketGateway implements TicketGateway {
   }
 }
 
+/**
+ * In-memory {@link UiPreferencesGateway} for tests/dev (ticket #29). Mirrors the
+ * localStorage adapter's best-effort JSON round-trip without touching the DOM,
+ * so persisted-filter behaviour can be exercised offline.
+ */
+export class MockUiPreferencesGateway implements UiPreferencesGateway {
+  private readonly store = new Map<string, string>();
+
+  read(key: string): unknown {
+    const raw = this.store.get(key);
+    if (raw === undefined) return null;
+    try {
+      return JSON.parse(raw);
+    } catch {
+      this.store.delete(key);
+      return null;
+    }
+  }
+
+  write(key: string, value: unknown): void {
+    try {
+      this.store.set(key, JSON.stringify(value));
+    } catch {
+      /* best-effort */
+    }
+  }
+
+  remove(key: string): void {
+    this.store.delete(key);
+  }
+}
+
 function mostRestrictive(
   project?: PermissionSet["fallback"],
   agent?: PermissionSet["fallback"],
@@ -2563,6 +2596,7 @@ export function createMockGateways(): Gateways {
     conversation: new MockConversationGateway(),
     ticket: new MockTicketGateway(systemGateway),
     window: new MockWindowGateway(),
+    uiPreferences: new MockUiPreferencesGateway(),
   };
 }
 

frontend/src/adapters/mock/mock.test.ts

@@ -31,6 +31,7 @@ describe("createMockGateways", () => {
       "template",
       "terminal",
       "ticket",
+      "uiPreferences",
       "window",
       "workState",
     ]);

frontend/src/adapters/uiPreferences.ts

@@ -0,0 +1,65 @@
+/**
+ * `localStorage`-backed {@link UiPreferencesGateway} (ticket #29).
+ *
+ * The only place that touches `window.localStorage`; features go through the
+ * port via DI. Everything is best-effort: a missing / private-mode / quota-full
+ * storage, or a corrupt JSON entry, degrades silently to "no preference" rather
+ * than throwing into the UI (persisted UI filters must never break the app).
+ */
+
+import type { UiPreferencesGateway } from "@/ports";
+
+/** Returns the `Storage` if usable in this environment, else `null`. */
+function storage(): Storage | null {
+  try {
+    return typeof window !== "undefined" ? window.localStorage : null;
+  } catch {
+    // Accessing `localStorage` can throw (sandboxed / disabled cookies).
+    return null;
+  }
+}
+
+export class LocalStorageUiPreferencesGateway implements UiPreferencesGateway {
+  read(key: string): unknown {
+    const store = storage();
+    if (!store) return null;
+    let raw: string | null;
+    try {
+      raw = store.getItem(key);
+    } catch {
+      return null;
+    }
+    if (raw === null) return null;
+    try {
+      return JSON.parse(raw);
+    } catch {
+      // Corrupt entry — drop it so we stop tripping over it, return default.
+      try {
+        store.removeItem(key);
+      } catch {
+        /* ignore */
+      }
+      return null;
+    }
+  }
+
+  write(key: string, value: unknown): void {
+    const store = storage();
+    if (!store) return;
+    try {
+      store.setItem(key, JSON.stringify(value));
+    } catch {
+      /* quota / serialisation failure — persistence is best-effort */
+    }
+  }
+
+  remove(key: string): void {
+    const store = storage();
+    if (!store) return;
+    try {
+      store.removeItem(key);
+    } catch {
+      /* ignore */
+    }
+  }
+}

frontend/src/features/tickets/TicketPicker.tsx

@@ -31,6 +31,7 @@ import type { TicketRef } from "@/domain";
 import type { TicketListQuery } from "@/ports";
 import { Button, Spinner, cn, zIndex } from "@/shared";
 import { TicketFacetsBar } from "./TicketFacetsBar";
+import { pickerFiltersKey } from "./ticketFilterPersistence";
 import { PriorityBadge, StatusBadge, TicketRef as TicketRefBadge } from "./ticketMeta";
 import {
   useTicketSearch,
@@ -55,6 +56,13 @@ export interface TicketPickerProps {
   excludeRefs?: TicketRef[];
   /** Seed filter/search query. */
   initialQuery?: TicketListQuery;
+  /**
+   * Whether the picker persists its filters across openings (ticket #29,
+   * default `true`). `initialQuery` still wins per field, so a caller imposing a
+   * business filter keeps priority; a caller that must never inherit stored
+   * preferences can opt out entirely with `false`.
+   */
+  persistFilters?: boolean;
   /**
    * Selection callback. In `"single"` mode it receives one
    * {@link TicketPickerResult}; in `"multi"` it receives the array.
@@ -76,6 +84,7 @@ export function TicketPicker({
   selectionMode = "single",
   excludeRefs,
   initialQuery,
+  persistFilters = true,
   onSelect,
   onClose,
 }: TicketPickerProps) {
@@ -88,6 +97,7 @@ export function TicketPicker({
       selectionMode={selectionMode}
       excludeRefs={excludeRefs}
       initialQuery={initialQuery}
+      persistFilters={persistFilters}
       onSelect={onSelect}
       onClose={onClose}
     />
@@ -106,16 +116,27 @@ function TicketPickerBody({
   selectionMode,
   excludeRefs,
   initialQuery,
+  persistFilters,
   onSelect,
   onClose,
 }: Required<
   Pick<
     TicketPickerProps,
-    "projectId" | "title" | "confirmLabel" | "selectionMode" | "onSelect" | "onClose"
+    | "projectId"
+    | "title"
+    | "confirmLabel"
+    | "selectionMode"
+    | "persistFilters"
+    | "onSelect"
+    | "onClose"
   >
 > &
   Pick<TicketPickerProps, "excludeRefs" | "initialQuery">) {
-  const vm = useTicketSearch(projectId, { initialQuery, excludeRefs });
+  const vm = useTicketSearch(projectId, {
+    initialQuery,
+    excludeRefs,
+    persistenceKey: persistFilters ? pickerFiltersKey(projectId) : undefined,
+  });
   const dialogRef = useRef<HTMLDivElement>(null);
   const [selecting, setSelecting] = useState(false);
   const [resolveError, setResolveError] = useState<string | null>(null);

frontend/src/features/tickets/TicketsPanel.tsx

@@ -7,7 +7,7 @@
  * through {@link useTickets}.
  */
 
-import { useState } from "react";
+import { useEffect, useState } from "react";
 
 import type { Sprint, TicketPriority, TicketSummary } from "@/domain";
 import { Button, Input, Panel, Spinner, cn } from "@/shared";
@@ -38,7 +38,21 @@ export interface TicketsPanelProps {
 
 export function TicketsPanel({ projectId, onOpen }: TicketsPanelProps) {
   const vm = useTickets(projectId);
-  const { agents, nameOf } = useProjectAgents(projectId);
+  const { agents, nameOf, loaded: agentsLoaded } = useProjectAgents(projectId);
+
+  // Reconcile a *restored* assignee filter (ticket #29) against the live roster:
+  // once the agents are known, an assignee that no longer exists is dropped
+  // (which also clears it from persisted storage via `useTickets`). Guarded on
+  // `agentsLoaded` so a still-valid assignee is never cleared during the load
+  // window when the roster is momentarily empty.
+  useEffect(() => {
+    if (!agentsLoaded) return;
+    const id = vm.query.assignedAgentId;
+    if (id && !agents.some((a) => a.id === id)) {
+      const { assignedAgentId: _drop, ...rest } = vm.query;
+      vm.setQuery(rest);
+    }
+  }, [agentsLoaded, agents, vm.query, vm.setQuery]);
   const [showCreate, setShowCreate] = useState(false);
   const [showSprints, setShowSprints] = useState(false);
   const [newTitle, setNewTitle] = useState("");

frontend/src/features/tickets/ticketFilterPersistence.test.ts

@@ -0,0 +1,116 @@
+import { describe, it, expect } from "vitest";
+
+import type { TicketListQuery } from "@/ports";
+import {
+  listFiltersKey,
+  parseTicketFilters,
+  pickerFiltersKey,
+  sanitizeListFilters,
+  sanitizePickerFilters,
+} from "./ticketFilterPersistence";
+
+describe("ticketFilterPersistence keys", () => {
+  it("scopes keys by project and surface (list vs picker disjoint)", () => {
+    expect(listFiltersKey("p1")).toBe("tickets:listFilters:p1");
+    expect(pickerFiltersKey("p1")).toBe("tickets:pickerFilters:p1");
+    expect(listFiltersKey("p1")).not.toBe(pickerFiltersKey("p1"));
+  });
+});
+
+describe("parseTicketFilters (validation)", () => {
+  it("returns an empty query for non-objects / corrupt input", () => {
+    expect(parseTicketFilters(null)).toEqual({});
+    expect(parseTicketFilters(undefined)).toEqual({});
+    expect(parseTicketFilters("nope")).toEqual({});
+    expect(parseTicketFilters(42)).toEqual({});
+    expect(parseTicketFilters([1, 2, 3])).toEqual({});
+  });
+
+  it("keeps only known statuses/priorities and drops unknown values", () => {
+    const parsed = parseTicketFilters({
+      statuses: ["open", "bogus", "QA", "open"],
+      priorities: ["high", "nope"],
+    });
+    expect(parsed.statuses).toEqual(["open", "QA"]); // deduped, unknown dropped
+    expect(parsed.priorities).toEqual(["high"]);
+  });
+
+  it("keeps valid text/sort/limit and rejects malformed ones", () => {
+    expect(parseTicketFilters({ text: "boom" }).text).toBe("boom");
+    expect(parseTicketFilters({ text: "" }).text).toBeUndefined();
+    expect(
+      parseTicketFilters({ sort: { field: "number", direction: "desc" } }).sort,
+    ).toEqual({ field: "number", direction: "desc" });
+    expect(
+      parseTicketFilters({ sort: { field: "bogus", direction: "desc" } }).sort,
+    ).toBeUndefined();
+    expect(parseTicketFilters({ limit: 50 }).limit).toBe(50);
+    expect(parseTicketFilters({ limit: -1 }).limit).toBeUndefined();
+    expect(parseTicketFilters({ limit: 1.5 }).limit).toBeUndefined();
+  });
+
+  it("never restores the opaque cursor", () => {
+    const parsed = parseTicketFilters({ text: "x", cursor: "opaque-token" });
+    expect(parsed.text).toBe("x");
+    expect("cursor" in parsed).toBe(false);
+  });
+
+  it("drops an obsolete assignee when it is not among the known agents", () => {
+    const raw = { assignedAgentId: "gone" };
+    // No roster provided → shape-only (assignee kept).
+    expect(parseTicketFilters(raw).assignedAgentId).toBe("gone");
+    // Roster provided and missing the id → assignee dropped.
+    expect(
+      parseTicketFilters(raw, { validAgentIds: new Set(["a1"]) }).assignedAgentId,
+    ).toBeUndefined();
+    // Roster provided and containing the id → kept.
+    expect(
+      parseTicketFilters(raw, { validAgentIds: new Set(["gone"]) })
+        .assignedAgentId,
+    ).toBe("gone");
+  });
+});
+
+describe("sanitize (persistable subsets)", () => {
+  const full: TicketListQuery = {
+    text: "hi",
+    statuses: ["open"],
+    priorities: ["high"],
+    assignedAgentId: "a1",
+    sort: { field: "title", direction: "asc" },
+    limit: 100,
+    cursor: "opaque",
+  };
+
+  it("list keeps assignee + limit but never cursor", () => {
+    const out = sanitizeListFilters(full)!;
+    expect(out).toEqual({
+      text: "hi",
+      statuses: ["open"],
+      priorities: ["high"],
+      assignedAgentId: "a1",
+      sort: { field: "title", direction: "asc" },
+      limit: 100,
+    });
+    expect("cursor" in out).toBe(false);
+  });
+
+  it("picker drops assignee, limit AND cursor", () => {
+    const out = sanitizePickerFilters(full)!;
+    expect(out).toEqual({
+      text: "hi",
+      statuses: ["open"],
+      priorities: ["high"],
+      sort: { field: "title", direction: "asc" },
+    });
+    expect("assignedAgentId" in out).toBe(false);
+    expect("limit" in out).toBe(false);
+    expect("cursor" in out).toBe(false);
+  });
+
+  it("returns null when nothing is worth persisting", () => {
+    expect(sanitizeListFilters({})).toBeNull();
+    expect(sanitizeListFilters({ cursor: "only-a-cursor" })).toBeNull();
+    expect(sanitizePickerFilters({ assignedAgentId: "a1" })).toBeNull();
+  });
+});

frontend/src/features/tickets/ticketFilterPersistence.ts

@@ -0,0 +1,231 @@
+/**
+ * Persistence of ticket filters across restarts / reopens (ticket #29).
+ *
+ * Frontend-only: filters are UI preferences, so they live behind the thin
+ * {@link UiPreferencesGateway} (localStorage adapter) — the backend stays the
+ * source of tickets, never of these preferences. Persistence is scoped **per
+ * project and per surface** through two disjoint keys so the main list and the
+ * {@link TicketPicker} popup never pollute each other:
+ *
+ *   - `tickets:listFilters:<projectId>`   — the main tickets window.
+ *   - `tickets:pickerFilters:<projectId>` — the reusable ticket picker.
+ *
+ * We only ever store the *stable* criteria (`text`, `statuses`, `priorities`,
+ * `sort`, `limit`, and — main list only — `assignedAgentId`). The opaque
+ * `cursor` is **never** persisted: it is a transient pagination token whose reuse
+ * across sessions is meaningless (G3-bis). Reads are defensive — unknown values
+ * are dropped and a corrupt blob yields the default empty query.
+ */
+
+import type { TicketPriority, TicketStatus } from "@/domain";
+import type {
+  TicketListQuery,
+  TicketListSort,
+  TicketListSortDirection,
+  TicketListSortField,
+  UiPreferencesGateway,
+} from "@/ports";
+
+const VALID_STATUSES: readonly TicketStatus[] = [
+  "open",
+  "inProgress",
+  "QA",
+  "closed",
+];
+const VALID_PRIORITIES: readonly TicketPriority[] = [
+  "low",
+  "medium",
+  "high",
+  "critical",
+];
+const VALID_SORT_FIELDS: readonly TicketListSortField[] = [
+  "number",
+  "priority",
+  "status",
+  "title",
+];
+const VALID_SORT_DIRECTIONS: readonly TicketListSortDirection[] = ["asc", "desc"];
+
+/** Storage key for the main tickets window, scoped to `projectId`. */
+export function listFiltersKey(projectId: string): string {
+  return `tickets:listFilters:${projectId}`;
+}
+
+/** Storage key for the {@link TicketPicker} popup, scoped to `projectId`. */
+export function pickerFiltersKey(projectId: string): string {
+  return `tickets:pickerFilters:${projectId}`;
+}
+
+function isObject(v: unknown): v is Record<string, unknown> {
+  return typeof v === "object" && v !== null && !Array.isArray(v);
+}
+
+/** Keeps only the members of `allowed`, de-duplicated, order preserved. */
+function filterEnumArray<T extends string>(
+  raw: unknown,
+  allowed: readonly T[],
+): T[] | undefined {
+  if (!Array.isArray(raw)) return undefined;
+  const set = new Set(allowed);
+  const out: T[] = [];
+  for (const v of raw) {
+    if (typeof v === "string" && set.has(v as T) && !out.includes(v as T)) {
+      out.push(v as T);
+    }
+  }
+  return out.length > 0 ? out : undefined;
+}
+
+function parseSort(raw: unknown): TicketListSort | undefined {
+  if (!isObject(raw)) return undefined;
+  const { field, direction } = raw;
+  if (
+    typeof field === "string" &&
+    (VALID_SORT_FIELDS as readonly string[]).includes(field) &&
+    typeof direction === "string" &&
+    (VALID_SORT_DIRECTIONS as readonly string[]).includes(direction)
+  ) {
+    return {
+      field: field as TicketListSortField,
+      direction: direction as TicketListSortDirection,
+    };
+  }
+  return undefined;
+}
+
+/** Options for {@link parseTicketFilters}. */
+export interface ParseTicketFiltersOptions {
+  /**
+   * When provided, a persisted `assignedAgentId` is kept only if it belongs to
+   * this set — an obsolete assignee (agent since deleted) is dropped. When
+   * `undefined`, the assignee is validated for *shape* only (the caller does not
+   * know the agent roster yet and reconciles later).
+   */
+  validAgentIds?: ReadonlySet<string>;
+}
+
+/**
+ * Validates an untrusted persisted blob into a clean {@link TicketListQuery}.
+ * Unknown fields/values are ignored; a non-object (corrupt JSON already yielded
+ * `null` upstream) yields the default empty query. `cursor` is never read back.
+ */
+export function parseTicketFilters(
+  raw: unknown,
+  options: ParseTicketFiltersOptions = {},
+): TicketListQuery {
+  if (!isObject(raw)) return {};
+  const query: TicketListQuery = {};
+
+  if (typeof raw.text === "string" && raw.text.length > 0) {
+    query.text = raw.text;
+  }
+
+  const statuses = filterEnumArray(raw.statuses, VALID_STATUSES);
+  if (statuses) query.statuses = statuses;
+
+  const priorities = filterEnumArray(raw.priorities, VALID_PRIORITIES);
+  if (priorities) query.priorities = priorities;
+
+  if (typeof raw.assignedAgentId === "string" && raw.assignedAgentId) {
+    const { validAgentIds } = options;
+    if (!validAgentIds || validAgentIds.has(raw.assignedAgentId)) {
+      query.assignedAgentId = raw.assignedAgentId;
+    }
+  }
+
+  const sort = parseSort(raw.sort);
+  if (sort) query.sort = sort;
+
+  if (
+    typeof raw.limit === "number" &&
+    Number.isInteger(raw.limit) &&
+    raw.limit > 0
+  ) {
+    query.limit = raw.limit;
+  }
+
+  // `cursor` is intentionally never restored.
+  return query;
+}
+
+/**
+ * Reduces a live query to the persistable subset for the **main list**: keeps
+ * `text/statuses/priorities/assignedAgentId/sort/limit`, drops `cursor`. Returns
+ * `null` when nothing is worth storing (so the caller can remove the key).
+ */
+export function sanitizeListFilters(query: TicketListQuery): TicketListQuery | null {
+  const out: TicketListQuery = {};
+  if (query.text) out.text = query.text;
+  if (query.statuses && query.statuses.length > 0) out.statuses = query.statuses;
+  if (query.priorities && query.priorities.length > 0) {
+    out.priorities = query.priorities;
+  }
+  if (query.assignedAgentId) out.assignedAgentId = query.assignedAgentId;
+  if (query.sort) out.sort = query.sort;
+  if (typeof query.limit === "number") out.limit = query.limit;
+  return Object.keys(out).length > 0 ? out : null;
+}
+
+/**
+ * Reduces a live query to the persistable subset for the **picker**: like the
+ * list but *without* `assignedAgentId` (assignee is a main-list-only preference)
+ * and without `limit` (the picker's limit is a caller/business concern, not a
+ * user preference). `cursor` is likewise dropped.
+ */
+export function sanitizePickerFilters(
+  query: TicketListQuery,
+): TicketListQuery | null {
+  const out: TicketListQuery = {};
+  if (query.text) out.text = query.text;
+  if (query.statuses && query.statuses.length > 0) out.statuses = query.statuses;
+  if (query.priorities && query.priorities.length > 0) {
+    out.priorities = query.priorities;
+  }
+  if (query.sort) out.sort = query.sort;
+  return Object.keys(out).length > 0 ? out : null;
+}
+
+/** Reads + validates the persisted main-list filters (empty query on miss). */
+export function hydrateListFilters(
+  prefs: UiPreferencesGateway | undefined,
+  projectId: string,
+  options?: ParseTicketFiltersOptions,
+): TicketListQuery {
+  if (!prefs) return {};
+  return parseTicketFilters(prefs.read(listFiltersKey(projectId)), options);
+}
+
+/** Persists (or clears) the main-list filters for a project. */
+export function persistListFilters(
+  prefs: UiPreferencesGateway | undefined,
+  projectId: string,
+  query: TicketListQuery,
+): void {
+  if (!prefs) return;
+  const sanitized = sanitizeListFilters(query);
+  const key = listFiltersKey(projectId);
+  if (sanitized) prefs.write(key, sanitized);
+  else prefs.remove(key);
+}
+
+/** Reads + validates the persisted picker filters (empty query on miss). */
+export function hydratePickerFilters(
+  prefs: UiPreferencesGateway | undefined,
+  projectId: string,
+): TicketListQuery {
+  if (!prefs) return {};
+  return parseTicketFilters(prefs.read(pickerFiltersKey(projectId)));
+}
+
+/** Persists (or clears) the picker filters for a project. */
+export function persistPickerFilters(
+  prefs: UiPreferencesGateway | undefined,
+  projectId: string,
+  query: TicketListQuery,
+): void {
+  if (!prefs) return;
+  const sanitized = sanitizePickerFilters(query);
+  const key = pickerFiltersKey(projectId);
+  if (sanitized) prefs.write(key, sanitized);
+  else prefs.remove(key);
+}

frontend/src/features/tickets/ticketFiltersPersistence.integration.test.tsx

@@ -0,0 +1,162 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+
+import { DIProvider } from "@/app/di";
+import {
+  MockAgentGateway,
+  MockSystemGateway,
+  MockTicketGateway,
+  MockUiPreferencesGateway,
+} from "@/adapters/mock";
+import type { Gateways } from "@/ports";
+import { TicketsPanel } from "./TicketsPanel";
+import { TicketPicker } from "./TicketPicker";
+import { listFiltersKey, pickerFiltersKey } from "./ticketFilterPersistence";
+
+const PROJECT_ID = "project-persist-test";
+
+describe("ticket #29 — persisted list filters (useTickets)", () => {
+  let system: MockSystemGateway;
+  let ticket: MockTicketGateway;
+  let agent: MockAgentGateway;
+  let prefs: MockUiPreferencesGateway;
+
+  beforeEach(() => {
+    system = new MockSystemGateway();
+    ticket = new MockTicketGateway(system);
+    agent = new MockAgentGateway();
+    prefs = new MockUiPreferencesGateway();
+  });
+
+  function renderPanel() {
+    const gateways = { system, ticket, agent, uiPreferences: prefs } as unknown as Gateways;
+    return render(
+      <DIProvider gateways={gateways}>
+        <TicketsPanel projectId={PROJECT_ID} onOpen={vi.fn()} />
+      </DIProvider>,
+    );
+  }
+
+  it("restores persisted list filters at mount", async () => {
+    prefs.write(listFiltersKey(PROJECT_ID), {
+      text: "restored-text",
+      statuses: ["open"],
+    });
+    renderPanel();
+    const search = (await screen.findByLabelText(
+      "search tickets",
+    )) as HTMLInputElement;
+    expect(search.value).toBe("restored-text");
+  });
+
+  it("persists a filter change (scoped to the list key)", async () => {
+    renderPanel();
+    const search = (await screen.findByLabelText(
+      "search tickets",
+    )) as HTMLInputElement;
+    fireEvent.change(search, { target: { value: "boom" } });
+    await waitFor(() => {
+      expect(prefs.read(listFiltersKey(PROJECT_ID))).toMatchObject({
+        text: "boom",
+      });
+    });
+    // The picker key stays untouched (surfaces do not pollute each other).
+    expect(prefs.read(pickerFiltersKey(PROJECT_ID))).toBeNull();
+  });
+
+  it("drops an obsolete persisted assignee once the roster is known", async () => {
+    prefs.write(listFiltersKey(PROJECT_ID), {
+      text: "keep-me",
+      assignedAgentId: "ghost-agent",
+    });
+    renderPanel();
+    // The roster (empty here) has no such agent → the assignee is reconciled out
+    // and re-persisted without it, while the rest of the filters survive.
+    await waitFor(() => {
+      const stored = prefs.read(listFiltersKey(PROJECT_ID)) as
+        | Record<string, unknown>
+        | null;
+      expect(stored).not.toBeNull();
+      expect(stored).toMatchObject({ text: "keep-me" });
+      expect("assignedAgentId" in (stored ?? {})).toBe(false);
+    });
+  });
+});
+
+describe("ticket #29 — persisted picker filters (TicketPicker)", () => {
+  let system: MockSystemGateway;
+  let ticket: MockTicketGateway;
+  let prefs: MockUiPreferencesGateway;
+
+  beforeEach(() => {
+    system = new MockSystemGateway();
+    ticket = new MockTicketGateway(system);
+    prefs = new MockUiPreferencesGateway();
+  });
+
+  function renderPicker(
+    props: Partial<React.ComponentProps<typeof TicketPicker>> = {},
+  ) {
+    const gateways = { system, ticket, uiPreferences: prefs } as unknown as Gateways;
+    return render(
+      <DIProvider gateways={gateways}>
+        <TicketPicker
+          open
+          projectId={PROJECT_ID}
+          onSelect={vi.fn()}
+          onClose={vi.fn()}
+          {...props}
+        />
+      </DIProvider>,
+    );
+  }
+
+  it("restores persisted picker filters on reopen", async () => {
+    prefs.write(pickerFiltersKey(PROJECT_ID), { text: "picker-pref" });
+    renderPicker();
+    const search = (await screen.findByLabelText(
+      "search tickets",
+    )) as HTMLInputElement;
+    expect(search.value).toBe("picker-pref");
+  });
+
+  it("lets initialQuery win over the persisted preference for imposed fields", async () => {
+    await ticket.create(PROJECT_ID, { title: "Open item", status: "open" });
+    const closed = await ticket.create(PROJECT_ID, { title: "Closed item" });
+    await ticket.update(PROJECT_ID, closed.ref, {
+      status: "closed",
+      expectedVersion: closed.version,
+    });
+    // The stored preference asks for "closed", but the caller imposes "open".
+    prefs.write(pickerFiltersKey(PROJECT_ID), { statuses: ["closed"] });
+    renderPicker({ initialQuery: { statuses: ["open"] } });
+    // initialQuery wins → the open item shows, the closed one is filtered out.
+    expect(await screen.findByText("Open item")).toBeTruthy();
+    expect(screen.queryByText("Closed item")).toBeNull();
+  });
+
+  it("never persists the opaque cursor, even after paginating", async () => {
+    for (let i = 0; i < 3; i += 1) {
+      await ticket.create(PROJECT_ID, { title: `Alpha ${i}` });
+    }
+    // Seed text so something is persisted; small limit forces a nextCursor.
+    renderPicker({ initialQuery: { text: "Alpha", limit: 2 } });
+    // Wait for the first page and its "Load more" (nextCursor present).
+    const loadMore = await screen.findByRole("button", { name: /load more/i });
+    fireEvent.click(loadMore);
+    await screen.findByText("Alpha 0");
+
+    await waitFor(() => {
+      const stored = prefs.read(pickerFiltersKey(PROJECT_ID)) as
+        | Record<string, unknown>
+        | null;
+      expect(stored).toMatchObject({ text: "Alpha" });
+    });
+    const stored = prefs.read(pickerFiltersKey(PROJECT_ID)) as Record<
+      string,
+      unknown
+    >;
+    expect("cursor" in stored).toBe(false);
+    expect("limit" in stored).toBe(false);
+  });
+});

frontend/src/features/tickets/useProjectAgents.ts

@@ -14,21 +14,35 @@ export interface ProjectAgents {
   agents: Agent[];
   /** Maps an agent id to a display name, falling back to a short id. */
   nameOf: (agentId: string) => string;
+  /**
+   * `true` once the agent roster has been fetched for the current project.
+   * Callers that reconcile persisted state against known agents (ticket #29)
+   * must wait for this so a valid assignee is not dropped during the load window.
+   */
+  loaded: boolean;
 }
 
 export function useProjectAgents(projectId: string): ProjectAgents {
   const { agent } = useGateways();
   const [agents, setAgents] = useState<Agent[]>([]);
+  const [loaded, setLoaded] = useState(false);
 
   useEffect(() => {
     let cancelled = false;
+    setLoaded(false);
     void agent
       .listAgents(projectId)
       .then((list) => {
-        if (!cancelled) setAgents(list);
+        if (!cancelled) {
+          setAgents(list);
+          setLoaded(true);
+        }
       })
       .catch(() => {
-        if (!cancelled) setAgents([]);
+        if (!cancelled) {
+          setAgents([]);
+          setLoaded(true);
+        }
       });
     return () => {
       cancelled = true;
@@ -43,5 +57,5 @@ export function useProjectAgents(projectId: string): ProjectAgents {
   const nameOf = (agentId: string): string =>
     byId.get(agentId) ?? `${agentId.slice(0, 8)}…`;
 
-  return { agents, nameOf };
+  return { agents, nameOf, loaded };
 }

frontend/src/features/tickets/useTicketSearch.ts

@@ -20,6 +20,11 @@
 
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 
+import {
+  parseTicketFilters,
+  sanitizePickerFilters,
+} from "./ticketFilterPersistence";
+
 import type {
   GatewayError,
   TicketPriority,
@@ -62,6 +67,16 @@ export interface UseTicketSearchOptions {
    * (#37) enables it so its independent query stays in sync with add/remove.
    */
   refreshOnEvents?: boolean;
+  /**
+   * Storage key under which this surface persists its filters (ticket #29). When
+   * set, the facets/text/sort are hydrated from it at mount and re-persisted on
+   * change — but **`initialQuery` wins per field**: any criterion the caller
+   * imposes (a business filter such as a sprint context) overrides the persisted
+   * preference for that field. `assignedAgentId`, `limit` and the opaque `cursor`
+   * are never persisted here (picker surface). When omitted, no persistence
+   * happens (default) so unrelated `useTicketSearch` call-sites are unaffected.
+   */
+  persistenceKey?: string;
 }
 
 export interface TicketSearchViewModel {
@@ -110,20 +125,48 @@ export function useTicketSearch(
   projectId: string,
   options: UseTicketSearchOptions = {},
 ): TicketSearchViewModel {
-  const { initialQuery, excludeRefs, debounceMs = 200, refreshOnEvents } =
-    options;
-  const { ticket, system } = useGateways();
+  const {
+    initialQuery,
+    excludeRefs,
+    debounceMs = 200,
+    refreshOnEvents,
+    persistenceKey,
+  } = options;
+  const { ticket, system, uiPreferences } = useGateways();
+
+  // Seed the initial facets/text/sort once (ticket #29): the persisted
+  // preference is the base, but `initialQuery` overrides it per field so a
+  // caller-imposed business filter always wins over a stored one.
+  const seedRef = useRef<{
+    statuses?: TicketStatus[];
+    priorities?: TicketPriority[];
+    assignedAgentId?: string;
+    text?: string;
+    sort?: TicketListSort;
+  } | null>(null);
+  if (seedRef.current === null) {
+    const persisted =
+      persistenceKey && uiPreferences
+        ? parseTicketFilters(uiPreferences.read(persistenceKey))
+        : {};
+    seedRef.current = {
+      statuses: initialQuery?.statuses ?? persisted.statuses,
+      priorities: initialQuery?.priorities ?? persisted.priorities,
+      assignedAgentId: initialQuery?.assignedAgentId ?? persisted.assignedAgentId,
+      text: initialQuery?.text ?? persisted.text,
+      sort: initialQuery?.sort ?? persisted.sort,
+    };
+  }
+  const seed = seedRef.current;
 
   const [facets, setFacets] = useState<Facets>({
-    statuses: initialQuery?.statuses,
-    priorities: initialQuery?.priorities,
-    assignedAgentId: initialQuery?.assignedAgentId,
+    statuses: seed.statuses,
+    priorities: seed.priorities,
+    assignedAgentId: seed.assignedAgentId,
   });
-  const [text, setText] = useState(initialQuery?.text ?? "");
+  const [text, setText] = useState(seed.text ?? "");
   const [debouncedText, setDebouncedText] = useState(text);
-  const [sort, setSort] = useState<TicketListSort | undefined>(
-    initialQuery?.sort,
-  );
+  const [sort, setSort] = useState<TicketListSort | undefined>(seed.sort);
 
   const [items, setItems] = useState<TicketSummary[]>([]);
   const [cursor, setCursor] = useState<string | undefined>(undefined);
@@ -149,6 +192,26 @@ export function useTicketSearch(
     return () => clearTimeout(id);
   }, [text, debounceMs]);
 
+  // Persist the picker's filters (ticket #29): text/statuses/priorities/sort
+  // only — never `assignedAgentId`, `limit` or the opaque `cursor`. Keyed by the
+  // caller-provided `persistenceKey`; a no-op when persistence is disabled.
+  useEffect(() => {
+    if (!persistenceKey || !uiPreferences) return;
+    const trimmed = debouncedText.trim();
+    const sanitized = sanitizePickerFilters({
+      ...(facets.statuses && facets.statuses.length > 0
+        ? { statuses: facets.statuses }
+        : {}),
+      ...(facets.priorities && facets.priorities.length > 0
+        ? { priorities: facets.priorities }
+        : {}),
+      ...(trimmed ? { text: trimmed } : {}),
+      ...(sort ? { sort } : {}),
+    });
+    if (sanitized) uiPreferences.write(persistenceKey, sanitized);
+    else uiPreferences.remove(persistenceKey);
+  }, [persistenceKey, uiPreferences, facets, debouncedText, sort]);
+
   // A key that changes whenever the effective query (minus cursor) changes, so
   // the first-page effect refetches exactly when a criterion moves.
   const queryKey = useMemo(

frontend/src/features/tickets/useTickets.ts

@@ -11,7 +11,7 @@
  * or out of a sprint. Sprint lifecycle events refresh the sprint list.
  */
 
-import { useCallback, useEffect, useMemo, useState } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 
 import {
   isSprintEvent,
@@ -25,6 +25,10 @@ import {
 } from "@/domain";
 import type { CreateTicketInput, TicketListQuery } from "@/ports";
 import { useGateways } from "@/app/di";
+import {
+  hydrateListFilters,
+  persistListFilters,
+} from "./ticketFilterPersistence";
 
 export interface TicketsViewModel {
   list: TicketList | null;
@@ -76,12 +80,33 @@ function describe(e: unknown): string {
 }
 
 export function useTickets(projectId: string): TicketsViewModel {
-  const { ticket, system } = useGateways();
+  const { ticket, system, uiPreferences } = useGateways();
   const [list, setList] = useState<TicketList | null>(null);
   const [sprints, setSprints] = useState<Sprint[]>([]);
   const [error, setError] = useState<string | null>(null);
   const [busy, setBusy] = useState(false);
-  const [query, setQuery] = useState<TicketListQuery>({});
+  // Hydrate the filters persisted for this project (ticket #29) on first render
+  // so reopening the window restores them without a flash of defaults. The
+  // assignee, if any, is validated for shape here and reconciled against the
+  // live agent roster by the panel (an obsolete assignee is then cleared).
+  const [query, setQuery] = useState<TicketListQuery>(() =>
+    hydrateListFilters(uiPreferences, projectId),
+  );
+
+  // Re-hydrate when the hosting project changes (the mounted hook is normally
+  // pinned to one project, but stay correct if `projectId` is swapped in place).
+  const hydratedProject = useRef(projectId);
+  useEffect(() => {
+    if (hydratedProject.current === projectId) return;
+    hydratedProject.current = projectId;
+    setQuery(hydrateListFilters(uiPreferences, projectId));
+  }, [projectId, uiPreferences]);
+
+  // Persist the filters (minus the opaque cursor) whenever they change, scoped
+  // to this project's list key.
+  useEffect(() => {
+    persistListFilters(uiPreferences, projectId, query);
+  }, [uiPreferences, projectId, query]);
 
   // Stable dependency key so `refresh` only changes when a filter actually does.
   const queryKey = useMemo(() => JSON.stringify(query), [query]);

frontend/src/ports/index.ts

@@ -971,6 +971,29 @@ export interface WindowGateway {
   ): Promise<Unsubscribe>;
 }
 
+/**
+ * Thin UI-preferences port (ticket #29). Persists small, per-surface pieces of
+ * UI state (like the ticket filters) so they survive a restart / reopen. This is
+ * **frontend-owned** state: the backend stays the source of tickets, never of UI
+ * preferences. Values are opaque JSON blobs addressed by an explicit string key;
+ * the adapter serialises/parses them. Reads are best-effort — an absent or
+ * corrupt entry yields `null` so callers fall back to their default state, and
+ * writes never throw (a full/blocked store degrades to "not persisted").
+ *
+ * Deliberately synchronous: hydration happens during a component's first render,
+ * so the persisted state is applied without a flash of default filters. The
+ * localStorage adapter is synchronous; a future async backend (Tauri store)
+ * would front this with an in-memory cache to keep the contract.
+ */
+export interface UiPreferencesGateway {
+  /** Reads and JSON-parses the blob at `key`; `null` when absent or invalid. */
+  read(key: string): unknown;
+  /** JSON-serialises and persists `value` at `key`. Best-effort (never throws). */
+  write(key: string, value: unknown): void;
+  /** Removes any persisted blob at `key`. Best-effort (never throws). */
+  remove(key: string): void;
+}
+
 /**
  * The full set of gateways the app depends on, injected via the DI provider.
  * The composition (real vs mock) is chosen in `app/`.
@@ -995,4 +1018,5 @@ export interface Gateways {
   conversation: ConversationGateway;
   ticket: TicketGateway;
   window: WindowGateway;
+  uiPreferences: UiPreferencesGateway;
 }