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/alembic/versions/004_flywheel_preference_events.py

@@ -0,0 +1,67 @@
+"""004_flywheel_preference_events
+
+Revision ID: 004
+Revises: 003
+Create Date: 2026-06-09
+Alembic 004: 飞轮信号表
+preference_events 一期建表写入
+preference_profile 二期预留，一期不建
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "004"
+down_revision: Union[str, None] = "003"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+_SIGNAL_TYPE = sa.Enum(
+    "text_select", "image_select", "approve",
+    "reject_with_reason", "regenerate",
+    name="signaltype",
+)
+_DATA_OWNERSHIP = sa.Enum("client_data", "platform_asset", name="dataownership")
+
+
+def upgrade() -> None:
+    op.create_table(
+        "preference_events",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("workspace_id", sa.BigInteger(), nullable=False),
+        sa.Column("product_id", sa.BigInteger(), nullable=False),
+        sa.Column("task_id", sa.BigInteger(), nullable=False),
+        sa.Column("user_id", sa.BigInteger(), nullable=False),
+        sa.Column("signal_type", _SIGNAL_TYPE, nullable=False),
+        sa.Column("signal_weight", sa.Integer(), nullable=False),
+        sa.Column("candidate_id", sa.BigInteger(), nullable=True),
+        sa.Column("angle_label", sa.String(64), nullable=True),
+        sa.Column("reason", sa.Text(), nullable=True),
+        sa.Column("signal_meta", sa.Text(), nullable=True),
+        sa.Column(
+            "data_ownership", _DATA_OWNERSHIP,
+            nullable=False, server_default="client_data",
+        ),
+        sa.Column(
+            "created_at", sa.DateTime(),
+            server_default=sa.text("now()"), nullable=False,
+        ),
+        sa.ForeignKeyConstraint(["product_id"], ["products.id"]),
+        sa.ForeignKeyConstraint(["task_id"], ["generation_tasks.id"]),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"]),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        "idx_preference_events_ws_product_created",
+        "preference_events",
+        ["workspace_id", "product_id", "created_at"],
+    )
+    # preference_profile 二期预留，一期不建
+
+
+def downgrade() -> None:
+    op.drop_index("idx_preference_events_ws_product_created", "preference_events")
+    op.drop_table("preference_events")
+    # MySQL 不支持 DROP TYPE，枚举存 VARCHAR 无需清理