Fix (beta): restore v2 (Whoosh) advanced-search query compatibility (#13010)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

src/documents/tests/search/conftest.py

@@ -1,11 +1,15 @@
 from __future__ import annotations
 
+import tempfile
 from typing import TYPE_CHECKING
 
 import pytest
+import tantivy
 
 from documents.search._backend import TantivyBackend
 from documents.search._backend import reset_backend
+from documents.search._schema import build_schema
+from documents.search._tokenizer import register_tokenizers
 
 if TYPE_CHECKING:
     from collections.abc import Generator
@@ -31,3 +35,11 @@ def backend() -> Generator[TantivyBackend, None, None]:
     finally:
         b.close()
         reset_backend()
+
+
+@pytest.fixture(scope="module")
+def index() -> tantivy.Index:
+    """A real Tantivy index for parse-acceptance tests (module scope for speed)."""
+    idx = tantivy.Index(build_schema(), path=tempfile.mkdtemp())
+    register_tokenizers(idx, "english")
+    return idx