test(data): validate ng-eventually read filter on the real ORM set

Adds a @data scenario (workshop/read-filter) that enables the lib's read filter on the
real reactive ORM set (via a FilterProbe + setupReadFilter harness helper, granting each
participation to its own user) and asserts useShape returns only the target user's
participations. Validates the trickiest piece — filtering a live DeepSignalSet — against the
broker. @data 9/9. Doc: read filter marked implemented & validated.

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

src/modules/workshop/features/read-filter.feature

@@ -0,0 +1,14 @@
+# language: fr
+@WORKSHOP @priority-1
+Fonctionnalité: Filtre de lecture (ng-eventually)
+  En tant que développeur
+  Je veux valider, contre le vrai broker, que le filtre de lecture de la lib
+  ne renvoie que les données autorisées pour l'utilisateur courant, sur le vrai
+  set réactif de l'ORM.
+
+  @data
+  Scénario: Le filtre ne renvoie que les participations autorisées
+    Étant donné le wallet contient des participations de plusieurs utilisateurs
+    Quand j'active le filtre de lecture pour l'utilisateur courant
+    Alors je ne vois que les participations de l'utilisateur courant
+    Et le filtre a masqué au moins une participation d'un autre utilisateur

src/modules/workshop/steps/data/read-filter.steps.ts

@@ -0,0 +1,62 @@
+import { Given, When, Then } from '@cucumber/cucumber';
+import { expect } from 'chai';
+import type { FestipodWorld } from '../../../../shared/support/world';
+
+// Validates ng-eventually's READ FILTER on the REAL ORM set, against the broker.
+// The harness grants each participation to its own `user`; with the filter on
+// for a chosen user, useShape must yield only that user's participations.
+
+Given('le wallet contient des participations de plusieurs utilisateurs', async function (this: FestipodWorld) {
+  // Deterministic: create two participations for two synthetic users on a
+  // synthetic event (isolated from real-event counts; joinEvent is idempotent on
+  // event+user, so this doesn't accumulate across runs).
+  await this.appFrame!.evaluate(async () => {
+    const td = (window as any).__testData;
+    await td.joinEvent('urn:rf:event', 'urn:rf:alice');
+    await td.joinEvent('urn:rf:event', 'urn:rf:bob');
+  });
+  await this.appFrame!.waitForFunction(
+    () => {
+      const ps = [...(window as any).__testData.participations];
+      return ps.some((p: any) => p.user === 'urn:rf:alice') && ps.some((p: any) => p.user === 'urn:rf:bob');
+    },
+    null,
+    { timeout: 15000 },
+  );
+  const data = await this.appFrame!.evaluate(() => {
+    const td = (window as any).__testData;
+    const parts = [...td.participations];
+    const targetUser = 'urn:rf:alice';
+    return {
+      targetUser,
+      total: parts.length,
+      ownCount: parts.filter((p: any) => p.user === targetUser).length,
+    };
+  });
+  (this as any).rf = data;
+  expect(data.ownCount, 'exactly one participation for the target user').to.equal(1);
+  expect(data.total, 'other users have participations too').to.be.greaterThan(data.ownCount);
+});
+
+When('j\'active le filtre de lecture pour l\'utilisateur courant', async function (this: FestipodWorld) {
+  const { targetUser } = (this as any).rf;
+  await this.appFrame!.evaluate((u: string) => (window as any).__testData.setupReadFilter(u), targetUser);
+  await this.appFrame!.waitForFunction(
+    () => (window as any).__readFilter?.ready === true,
+    null,
+    { timeout: 15000 },
+  );
+});
+
+Then('je ne vois que les participations de l\'utilisateur courant', async function (this: FestipodWorld) {
+  const r = await this.appFrame!.evaluate(() => (window as any).__readFilter);
+  const { targetUser, ownCount } = (this as any).rf;
+  expect(r.users.every((u: string) => u === targetUser), 'all filtered participations belong to the target user').to.be.true;
+  expect(r.count, 'filtered count equals the target user own participations').to.equal(ownCount);
+});
+
+Then('le filtre a masqué au moins une participation d\'un autre utilisateur', async function (this: FestipodWorld) {
+  const r = await this.appFrame!.evaluate(() => (window as any).__readFilter);
+  const { total } = (this as any).rf;
+  expect(total, 'the filter hid at least one other-user participation').to.be.greaterThan(r.count);
+});

src/shared/test-harness/harness-ng.tsx

@@ -12,6 +12,7 @@ import { createRoot } from 'react-dom/client';
 import { NextGraphProvider, useNextGraph } from '../context/NextGraphContext';
 import { FestipodDataProvider, useFestipodData } from '../context/FestipodDataContext';
 import { useShape } from '@ng-eventually/client';
+import { setGrantOf, setCurrentUser } from '@ng-eventually/client/polyfill';
 import type { DeepSignalSet } from '@ng-eventually/client';
 import {
   FpEventShapeType,
@@ -67,6 +68,8 @@ function ConnectedHarness() {
   const participations = useShape(FpParticipationShapeType, privateNuri) as DeepSignalSet<FpParticipation>;
 
   const [bridgeReady, setBridgeReady] = useState(false);
+  // Read-filter validation: when set, <FilterProbe> mounts a filtered useShape.
+  const [filterUser, setFilterUser] = useState<string | null>(null);
 
   useEffect(() => {
     // Small delay for useShape to populate
@@ -146,6 +149,19 @@ function ConnectedHarness() {
         loadTestData() {
           return bootstrapWallet(events as any, users as any, participations as any);
         },
+
+        /**
+         * Enable the lib's READ FILTER on the real ORM set: each participation is
+         * granted to its own `user`, and the current user is `user`. <FilterProbe>
+         * then exposes window.__readFilter with the filtered participations.
+         */
+        setupReadFilter(user: string) {
+          setGrantOf((item: any) =>
+            item && item.user ? { read: [item.user], write: [item.user] } : undefined,
+          );
+          setCurrentUser(user);
+          setFilterUser(user);
+        },
       };
 
       console.log('[HarnessNG] Ready — events:', events.size, 'users:', users.size,
@@ -157,7 +173,30 @@ function ConnectedHarness() {
     return () => clearTimeout(timer);
   }, [events, users, participations, ngCtx, appData]);
 
-  return <div id="harness-status">{bridgeReady ? 'READY' : 'LOADING_SHAPES'}</div>;
+  return (
+    <>
+      <div id="harness-status">{bridgeReady ? 'READY' : 'LOADING_SHAPES'}</div>
+      {filterUser && privateNuri && <FilterProbe privateNuri={privateNuri} />}
+    </>
+  );
+}
+
+// ============================================================================
+// FilterProbe — subscribes participations AFTER the read filter is enabled, so
+// useShape returns a filtered view. Exposes window.__readFilter for the @data
+// scenario validating the read filter on the real ORM set.
+// ============================================================================
+
+function FilterProbe({ privateNuri }: { privateNuri: string }) {
+  const set = useShape(FpParticipationShapeType, privateNuri) as DeepSignalSet<FpParticipation>;
+  useEffect(() => {
+    (window as any).__readFilter = {
+      ready: true,
+      count: set.size,
+      users: [...set].map(p => p.user),
+    };
+  }, [set]);
+  return null;
 }
 
 // ============================================================================