test(instagram): add tests for anonymous profile and hashtag discovery

Introduced new tests to validate the behavior of the Instagram scraper when discovering anonymous profiles and handling hashtag searches. The tests ensure that profile lookups succeed without requiring authentication, while hashtag searches correctly raise an error when access is blocked, enhancing the robustness of the scraper's functionality.

surfsense_backend/tests/unit/platforms/instagram/test_fetch_resilience.py

@@ -389,3 +389,22 @@ async def test_scrape_instagram_closes_sessions_when_limit_stops_inflight_worker
     assert len(items) == 3
     assert holders, "workers should have opened sessions"
     assert all(h.closed for h in holders), "early stop leaked a proxy session"
+
+
+async def test_discover_profile_is_anonymous_handle_lookup():
+    # keyword search (topsearch) is login-walled, so a profile/user query resolves
+    # as a DIRECT handle lookup against the anonymous profile endpoint — no network
+    # here, just the URL resolution, so no session/monkeypatch needed.
+    targets = await scraper._discover("messi", search_type="user", limit=10)
+    assert [(t.kind, t.value) for t in targets] == [("profile", "messi")]
+
+
+async def test_discover_hashtag_search_blocks_anonymously():
+    # hashtag/place keyword discovery has no anonymous endpoint at all, so it must
+    # fail loud (clear message) rather than return a misleading empty success.
+    raised = False
+    try:
+        await scraper._discover("travel", search_type="hashtag", limit=10)
+    except InstagramAccessBlockedError:
+        raised = True
+    assert raised