refactor(api): establish dataset application boundaries (#41729)

Co-authored-by: Jyong <jyong@dify.ai>

api/fields/segment_fields.py

@@ -1,10 +1,6 @@
-from collections.abc import Iterable, Mapping
-from dataclasses import dataclass
 from datetime import datetime
-from typing import Any
 
 from pydantic import field_serializer
-from sqlalchemy.orm import Session
 
 from fields.base import ResponseModel
 from libs.helper import to_timestamp
@@ -72,40 +68,6 @@ class SegmentResponse(ResponseModel):
         return to_timestamp(value)
 
 
-@dataclass(frozen=True)
-class SegmentWithSummary:
-    """Expose session-backed segment relations during response validation."""
-
-    segment: Any
-    summary: str | None
-    session: Session
-
-    @property
-    def child_chunks(self) -> Any:
-        return self.segment.get_child_chunks(session=self.session, include_full_doc=False)
-
-    @property
-    def attachments(self) -> Any:
-        return self.segment.get_attachments(session=self.session)
-
-    def __getattr__(self, name: str) -> Any:
-        return getattr(self.segment, name)
-
-
-def segment_response_with_summary(segment: Any, summary: str | None, *, session: Session) -> SegmentResponse:
-    response_source = SegmentWithSummary(segment=segment, summary=summary, session=session)
-    return SegmentResponse.model_validate(response_source, from_attributes=True)
-
-
-def segment_responses_with_summaries(
-    segments: Iterable[Any],
-    summaries: Mapping[str, str | None],
-    *,
-    session: Session,
-) -> list[SegmentResponse]:
-    return [segment_response_with_summary(segment, summaries.get(segment.id), session=session) for segment in segments]
-
-
 class SegmentDetailResponse(ResponseModel):
     data: SegmentResponse
     doc_form: str