baseline: Clover 独立仓库首次基线提交

将 Clover 从上层产品包旧仓库中独立出来,建立专属版本控制。
当前状态=纵切片端到端已打通(登录→选品→出文出图→审核→下载包),
M1文案质量去套路化已验收。此提交作为后续按核销清单逐条修复的基线。

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

backend/app/services/flywheel_service.py

@@ -0,0 +1,121 @@
+"""
+app/services/flywheel_service.py — 飞轮信号写入 + 偏好上下文聚合
+preference_collector：三信号入口（选文案/选图/审核）写入 preference_events。
+preference_aggregator：查最近50条 → 最常选角度 + 打回原因近3条原文拼 prompt。
+飞轮不暴露独立埋点端点，只由业务接口内部调用（契约红线）。
+"""
+
+import logging
+from typing import Any
+
+from sqlalchemy import desc, func
+from sqlalchemy.orm import Session
+
+from app.constants.enums import SIGNAL_WEIGHTS, DataOwnership, SignalType
+from app.middleware.workspace_guard import CurrentUser
+from app.models.flywheel import PreferenceEvent
+from app.models.task import GenerationTask
+
+logger = logging.getLogger(__name__)
+
+# 实时聚合窗口：最近50条事件
+_AGGREGATION_WINDOW = 50
+# 冷启动阈值：不足5条信号用产品档案冷启动
+_COLD_START_THRESHOLD = 5
+
+
+def record_signal(
+    db: Session,
+    current_user: CurrentUser,
+    task: GenerationTask,
+    signal_type: str,
+    candidate_id: int | None = None,
+    angle_label: str | None = None,
+    reason: str | None = None,
+) -> None:
+    """
+    写入飞轮信号。
+    workspace_id + product_id 都必须有（基石C + 按产品分开学）。
+    signal_weight 用枚举默认值，北哥可校准。
+    data_ownership 默认 client_data（选择行为归客户）。
+    """
+    weight = SIGNAL_WEIGHTS.get(signal_type, 0)
+    event = PreferenceEvent(
+        workspace_id=current_user.workspace_id,
+        product_id=task.product_id,
+        task_id=task.id,
+        user_id=current_user.user_id,
+        signal_type=signal_type,
+        signal_weight=weight,
+        candidate_id=candidate_id,
+        angle_label=angle_label,
+        reason=reason,
+        data_ownership=DataOwnership.CLIENT_DATA,
+    )
+    try:
+        db.add(event)
+        db.commit()
+        logger.info(
+            "Flywheel signal: type=%s weight=%s user=%s product=%s",
+            signal_type, weight, current_user.user_id, task.product_id,
+        )
+    except Exception:
+        db.rollback()
+        logger.error(
+            "Failed to write preference_event: type=%s user=%s",
+            signal_type, current_user.user_id,
+        )
+        raise
+
+
+def get_preference_context(
+    db: Session, workspace_id: int, product_id: int
+) -> dict[str, Any]:
+    """
+    实时聚合偏好上下文（最近50条 events）。
+    返回：recent_preference摘要 + reject_reasons近3条 + injected_count。
+    不足5条 → 冷启动提示（产品档案兜底，由 AIE prompt 层读 products.custom_prompt）。
+    按 workspace_id + product_id 严格过滤（不串数据，基石C）。
+    """
+    recent = (
+        db.query(PreferenceEvent)
+        .filter(
+            PreferenceEvent.workspace_id == workspace_id,
+            PreferenceEvent.product_id == product_id,
+        )
+        .order_by(desc(PreferenceEvent.created_at))
+        .limit(_AGGREGATION_WINDOW)
+        .all()
+    )
+
+    if len(recent) < _COLD_START_THRESHOLD:
+        return {
+            "recent_preference": "信号不足，使用产品档案基线（冷启动）",
+            "reject_reasons": [],
+            "injected_count": len(recent),
+        }
+
+    # 统计最常被选中的角度
+    angle_counts: dict[str, int] = {}
+    for ev in recent:
+        if ev.signal_type in (SignalType.TEXT_SELECT, SignalType.APPROVE) and ev.angle_label:
+            angle_counts[ev.angle_label] = angle_counts.get(ev.angle_label, 0) + 1
+
+    top_angles = sorted(angle_counts.items(), key=lambda x: x[1], reverse=True)[:3]
+    if top_angles:
+        pref_desc = "；".join(f"{a}（已选{c}次）" for a, c in top_angles)
+        preference_summary = f"最近偏好：{pref_desc}"
+    else:
+        preference_summary = "暂无明显角度偏好"
+
+    # 取最近3条打回原因原文（不做 AI 归纳，契约§3）
+    reject_reasons = [
+        ev.reason for ev in recent
+        if ev.signal_type == SignalType.REJECT_WITH_REASON and ev.reason
+    ][:3]
+
+    return {
+        "recent_preference": preference_summary,
+        "reject_reasons": reject_reasons,
+        "injected_count": len(recent),
+    }