第11环裂变重写：对齐上线版 split.js 一次LLM出N套完整笔记包

架构从"扇出N个GenerationTask各跑完整管道"改为"一次LLM调用直接出N套
完整笔记包(N=1~5)"，落 FissionNote 表 + 独立展示页。

后端：
- 018迁移：fission_notes 表(文案JSON+score+passed+imagePlan+images+status)
- fission_prompt：FISSION_SYSTEM+三档参考度(low/mid/high)+normalize_tags+品类兜底
- fission_pipeline：一次LLM出N套→各评分(@80合格线)→排序→落库,不达标标
  needs_optimization 非丢弃；apiports 503 回落 codeproxy gpt-5.5 强档兜底
- fission_images：每套串行调现有生图接口(零改动image_gen/storyboard)
- tasks.py：run_fission_pipeline Celery task，删旧扇出注入
- api/v1/fission：进度聚合FissionNote + GET /fission/{id}/notes(剥内部字段)

前端：FissionProgress对齐状态机 + N套独立展示页 + FissionNoteCard

测试：test_fission_engine(19)+test_fission_pipeline(5) 全过；104 全量回归绿

实测task5(fanout=2,mid)端到端跑通：一次出2套→seq0=85过/seq1=79标优化→
生图codeproxy/edits→1024×1536去AI化→task completed→notes端点返完整数据

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/api/v1/fission.py

@@ -1,10 +1,12 @@
 """
-app/api/v1/fission.py — 第11环裂变路由
+app/api/v1/fission.py — 第11环裂变路由（对齐上线版 split.js：一次出N套）
 
-POST /fission           触发裂变(1源任务→N套子任务)
-GET  /fission/{id}      查裂变进度(聚合N个子任务状态)
-工作台内呈现,子任务走标准 SSE 流回进度。
+POST /fission              触发裂变(1源任务→一次LLM出N套完整笔记包)
+GET  /fission/{id}         查裂变进度(聚合 FissionNote 落库/生图状态)
+GET  /fission/{id}/notes   取 N 套完整笔记包(独立展示页用)
+工作台内呈现，N 套笔记落 FissionNote 表，非扇出 GenerationTask。
 """
+import json
 import logging
 from typing import Annotated
 
@@ -15,8 +17,7 @@ from sqlalchemy.orm import Session
 from app.core.database import get_db
 from app.core.response import ok, raise_not_found
 from app.middleware.workspace_guard import CurrentUser, require_write_permission
-from app.models.fission import FissionTask
-from app.models.task import GenerationTask
+from app.models.fission import FissionTask, FissionNote
 
 logger = logging.getLogger(__name__)
 router = APIRouter(tags=["fission"])
@@ -34,13 +35,13 @@ def create_fission_endpoint(
     current_user: Annotated[CurrentUser, Depends(require_write_permission)] = None,
     db: Session = Depends(get_db),
 ):
-    """触发裂变：从源任务扇出 N 套完整笔记包。返回 fission_id + 子 task_ids。"""
+    """触发裂变：从源任务一次出 N 套完整笔记包。返回 fission_id。"""
     from app.services.fission_service import create_fission
-    fission_id, task_ids = create_fission(
+    fission_id, _ = create_fission(
         db, current_user, body.source_task_id, body.reference_level, body.fanout_count,
     )
-    return ok({"fission_id": fission_id, "task_ids": task_ids,
-               "reference_level": body.reference_level, "fanout_count": len(task_ids)})
+    return ok({"fission_id": fission_id,
+               "reference_level": body.reference_level, "fanout_count": body.fanout_count})
 
 
 @router.get("/fission/{fission_id}")
@@ -49,7 +50,7 @@ def get_fission_progress(
     current_user: Annotated[CurrentUser, Depends(require_write_permission)] = None,
     db: Session = Depends(get_db),
 ):
-    """查裂变进度：聚合 N 个子任务状态（x/N 完成）。"""
+    """查裂变进度：聚合 FissionNote 落库/生图状态（x/N 完成）。"""
     ft = db.query(FissionTask).filter(
         FissionTask.id == fission_id,
         FissionTask.workspace_id == current_user.workspace_id,
@@ -57,22 +58,60 @@ def get_fission_progress(
     if not ft:
         raise_not_found("裂变任务不存在")
 
-    subs = db.query(GenerationTask).filter(
-        GenerationTask.source_fission_id == fission_id,
-        GenerationTask.workspace_id == current_user.workspace_id,
+    notes = db.query(FissionNote).filter(
+        FissionNote.fission_id == fission_id,
+        FissionNote.workspace_id == current_user.workspace_id,
     ).all()
-    done_states = {"pending_selection", "pending_review", "approved", "archived"}
-    done = sum(1 for s in subs if s.status in done_states)
-    failed = sum(1 for s in subs if s.status == "failed")
-    total = len(subs)
-    # 聚合状态：全失败=failed,全完成=done,否则generating
-    agg = "done" if done == total and total > 0 else ("failed" if failed == total and total > 0 else "generating")
-    if ft.status != agg:
-        ft.status = agg; db.commit()
-
+    done = sum(1 for n in notes if n.status == "image_done")
+    failed = sum(1 for n in notes if n.status == "failed")
+    total = len(notes)
+    # FissionTask.status 由 pipeline 维护(generating→completed/failed)；此处只读不改，
+    # 避免 API 轮询与 worker 写状态打架。进度数 = 已落库套数的生图完成度。
     return ok({
         "fission_id": ft.id, "reference_level": ft.reference_level,
-        "fanout_count": ft.fanout_count, "status": agg,
+        "fanout_count": ft.fanout_count, "status": ft.status,
         "progress": {"done": done, "failed": failed, "total": total},
-        "task_ids": [s.id for s in subs],
     })
+
+
+@router.get("/fission/{fission_id}/notes")
+def get_fission_notes(
+    fission_id: int,
+    current_user: Annotated[CurrentUser, Depends(require_write_permission)] = None,
+    db: Session = Depends(get_db),
+):
+    """取 N 套完整笔记包（独立展示页用）：每套含文案+标签+imagePlan+图+分数。"""
+    ft = db.query(FissionTask).filter(
+        FissionTask.id == fission_id,
+        FissionTask.workspace_id == current_user.workspace_id,
+    ).first()
+    if not ft:
+        raise_not_found("裂变任务不存在")
+
+    rows = db.query(FissionNote).filter(
+        FissionNote.fission_id == fission_id,
+        FissionNote.workspace_id == current_user.workspace_id,
+    ).order_by(FissionNote.seq.asc()).all()
+
+    notes = []
+    for r in rows:
+        try:
+            note = json.loads(r.note_json) if r.note_json else {}
+        except (ValueError, TypeError):
+            note = {}
+        try:
+            images = json.loads(r.images_json) if r.images_json else []
+        except (ValueError, TypeError):
+            images = []
+        # 内部评分中间字段(_score/_passed/_block)不外泄，前端用平铺的 score/passed
+        for k in ("_score", "_passed", "_block"):
+            note.pop(k, None)
+        notes.append({
+            "seq": r.seq, "note": note, "images": images,
+            "score": r.score, "passed": bool(r.passed),
+            "needs_optimization": bool(r.needs_optimization),
+            "dimension": r.dimension, "status": r.status,
+        })
+
+    return ok({"fission_id": ft.id, "status": ft.status,
+               "fanout_count": ft.fanout_count, "notes": notes})