refactor(search): move SearchQueryError family to _query.py, add InvalidNumberQuery/MultipleSearchQueryErrors

Move SearchQueryError and InvalidDateQuery from _translate.py to _query.py and
add two new exception classes: InvalidNumberQuery and MultipleSearchQueryErrors.
Update _translate.py to re-export the exceptions for backward compatibility
until the translation module is removed. Update __init__.py to export all
four exception classes from _query.py.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/documents/search/_query.py

@@ -9,15 +9,54 @@ import tantivy
 from django.conf import settings
 
 from documents.search._tokenizer import simple_search_tokens
-from documents.search._translate import SearchQueryError
-from documents.search._translate import translate_query
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
+    from collections.abc import Sequence
     from datetime import tzinfo
 
     from django.contrib.auth.base_user import AbstractBaseUser
 
+
+class SearchQueryError(ValueError):
+    """
+    Base for user-fixable search query errors.
+
+    Carries a message safe to surface to the user (no internal details). The
+    view layer catches this and returns an HTTP 400, so any future subclass
+    gets the same treatment.
+    """
+
+
+class InvalidDateQuery(SearchQueryError):
+    """Raised when a date field value or range bound cannot be parsed."""
+
+    def __init__(self, field: str | None, value: str | None) -> None:
+        self.field = field
+        self.value = value
+        super().__init__(f"Invalid date value {value!r} for field {field!r}.")
+
+
+class InvalidNumberQuery(SearchQueryError):
+    """Raised when a numeric field value or range bound cannot be parsed."""
+
+    def __init__(self, field: str | None, value: str | None) -> None:
+        self.field = field
+        self.value = value
+        super().__init__(f"Invalid numeric value {value!r} for field {field!r}.")
+
+
+class MultipleSearchQueryErrors(SearchQueryError):
+    """Aggregates every user-fixable error from one parse, not just the first."""
+
+    def __init__(self, errors: Sequence[SearchQueryError]) -> None:
+        self.errors = tuple(errors)
+        super().__init__("; ".join(str(e) for e in self.errors))
+
+
+# Import after exception definitions to avoid circular imports
+from documents.search._translate import translate_query  # noqa: E402
+
 logger = logging.getLogger("paperless.search")
 
 # Maximum seconds any single regex substitution may run.