fix(event_session): restore event_presentation/presenter_li_qry_str fields

These fields from v_event_session_w_file_count were lost during the v1/v2
-> v3 migration. Added to Event_Session_Base model and to searchable_fields
in the event_session object definition.

Fields are only available via the alt view (v_event_session_w_file_count).
To search: use ?view=alt on the nested search endpoint.
To retrieve: use ?inc_file_count=true on the GET endpoint.

Also:
- Updated ARCH__V3_DEVELOPMENT_STANDARDS.md: expanded Field Evolution
  Checklist with alt-view field rules, Docker restart requirement, and
  documented the ?view= parameter as a live (not proposed) feature.
- Updated TODO__Agents.md: marked migration gap audit as complete.
- Added regression test to test_e2e_v3_search_engine.py.

tests/e2e/test_e2e_v3_search_engine.py

@@ -64,17 +64,72 @@ def test_extra_filters():
     resp = requests.get(f"{API_BASE}/user/?enabled=all&hidden=all", headers=get_headers())
     print_result("Bypass Filters (enabled=all)", resp.status_code == 200)
 
+def test_event_session_qry_str_fields():
+    """
+    Regression test for event_presentation_li_qry_str and event_presenter_li_qry_str.
+    These fields were lost during the v1/v2 -> v3 migration and restored May 2026.
+    They live in v_event_session_w_file_count (triggered by ?inc_file_count=true).
+
+    Demo session: DOW3h7v6H42 "How To Do Things" under Demo event pjrcghqwert
+    """
+    print("\n--- Testing event_session qry_str fields (regression: May 2026) ---")
+
+    EVENT_ID = "pjrcghqwert"
+    SESSION_ID = "DOW3h7v6H42"
+
+    headers = {
+        "Content-Type": "application/json",
+        "X-Aether-API-Key": API_KEY,
+        "x-no-account-id": "bypass"
+    }
+
+    # 1. Verify fields are returned in the GET response when inc_file_count=true
+    url = f"{API_BASE}/event_session/{SESSION_ID}?inc_file_count=true"
+    resp = requests.get(url, headers=headers)
+    ok = resp.status_code == 200
+    print_result("GET event_session with inc_file_count", ok, f"(status={resp.status_code})")
+    if ok:
+        data = resp.json().get("data", {})
+        has_pres = "event_presentation_li_qry_str" in data
+        has_presenter = "event_presenter_li_qry_str" in data
+        print_result("Field present: event_presentation_li_qry_str", has_pres,
+                     f"(value={data.get('event_presentation_li_qry_str')!r})")
+        print_result("Field present: event_presenter_li_qry_str", has_presenter,
+                     f"(value={data.get('event_presenter_li_qry_str')!r})")
+
+    # 2. Verify searching by event_presentation_li_qry_str via ?view=alt (v_event_session_w_file_count)
+    # These fields only exist in the alt view, so ?view=alt is required.
+    search_url = f"{API_BASE}/event/{EVENT_ID}/event_session/search?view=alt"
+    query = {"and": [{"field": "event_presentation_li_qry_str", "op": "like", "value": "%"}]}
+    resp = requests.post(search_url, headers=headers, json=query)
+    print_result("Search by event_presentation_li_qry_str (?view=alt)", resp.status_code == 200,
+                 f"(status={resp.status_code})")
+
+    # 3. Verify searching by event_presenter_li_qry_str via ?view=alt
+    query = {"and": [{"field": "event_presenter_li_qry_str", "op": "like", "value": "%"}]}
+    resp = requests.post(search_url, headers=headers, json=query)
+    print_result("Search by event_presenter_li_qry_str (?view=alt)", resp.status_code == 200,
+                 f"(status={resp.status_code})")
+
+    # 4. Confirm search on default view still rejects these fields (expected 400 — not in v_event_session)
+    search_url_default = f"{API_BASE}/event/{EVENT_ID}/event_session/search"
+    query = {"and": [{"field": "event_presentation_li_qry_str", "op": "like", "value": "%"}]}
+    resp = requests.post(search_url_default, headers=headers, json=query)
+    print_result("Search on default view correctly rejects qry_str field (expect 400)", resp.status_code == 400,
+                 f"(status={resp.status_code})")
+
 if __name__ == "__main__":
     print(f"Starting Consolidated Search Engine E2E Suite")
     print(f"Target: {API_BASE}")
-    
+
     start_time = time.time()
     try:
         test_basic_operators()
         test_registry_fields()
         test_nested_search()
         test_extra_filters()
+        test_event_session_qry_str_fields()
     except Exception as e:
         print(f"💥 Suite Error: {e}")
-    
+
     print(f"\nSuite completed in {time.time() - start_time:.2f}s")