fix(plugins): accept weak catalog etags

tests/unit/coding-plugin-marketplace-client.test.ts

@@ -350,6 +350,34 @@ describe('Marketplace client and account cache', () => {
     await expect(client.readCatalog({ limit: 10 })).resolves.toMatchObject({ stale: true, total: 1 });
   });
 
+  it('accepts a weak composite ETag from compressed Marketplace responses and reuses it verbatim', async () => {
+    const pricingVersionId = '00000000-0000-0000-0000-000000000420';
+    const etag = `W/"plugins-2-tp-${pricingVersionId}"`;
+    const fetcher = vi.fn<typeof fetch>()
+      .mockResolvedValueOnce(response({ ...catalogPage, catalog_generation: 2 }, {}, {
+        ETag: etag,
+        'X-Plugin-Catalog-Generation': '2',
+        'X-Token-Point-Pricing-Version': pricingVersionId,
+      }))
+      .mockResolvedValueOnce(new Response(null, { status: 304 }));
+    const client = createMarketplaceClient({
+      fetchImpl: fetcher,
+      apiBaseUrl: 'https://square.example',
+      getAccessToken: async () => null,
+      subscribeSession: () => () => undefined,
+    });
+
+    await expect(client.readCatalog({ limit: 10 })).resolves.toMatchObject({
+      total: 1,
+      etag,
+      generation: 2,
+      pricingVersionId,
+      stale: false,
+    });
+    await expect(client.readCatalog({ limit: 10 })).resolves.toMatchObject({ etag, stale: false });
+    expect(fetcher.mock.calls[1]?.[1]?.headers).toMatchObject({ 'If-None-Match': etag });
+  });
+
   it('refreshes download authentication at most once before accepting the artifact', async () => {
     const archive = Buffer.from('signed-artifact');
     const { grant } = signedGrant(archive);