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/006_image_role_varchar.py

@@ -0,0 +1,45 @@
+"""006_image_role_varchar — image_candidates.role 从 enum 改 varchar(32)
+
+根因：storyboard 角色名仍在演进（hook/product_closeup/ingredient/texture/
+applied_proof/closer/pain_scene/social_proof/scenario/tutorial…），固定 enum
+每加一个新角色就要迁一次，且旧 enum 漏了 product_closeup/ingredient 直接导致
+落库 "Data truncated for column 'role'" → 生图任务无限重试卡死。
+改 varchar 后落库不再受 enum 约束，角色名由 ImageRole 枚举在应用层定义。
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "006"
+down_revision = "005"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.alter_column(
+        "image_candidates",
+        "role",
+        existing_type=sa.Enum(
+            "hook", "pain", "proof", "quality", "credit", "convert", "main",
+            name="role",
+        ),
+        type_=sa.String(32),
+        existing_nullable=False,
+        server_default="hook",
+        comment="分镜角色名（storyboard 输出，应用层 ImageRole 定义，不在 DB 约束）",
+    )
+
+
+def downgrade() -> None:
+    op.alter_column(
+        "image_candidates",
+        "role",
+        existing_type=sa.String(32),
+        type_=sa.Enum(
+            "hook", "pain", "proof", "quality", "credit", "convert", "main",
+            name="role",
+        ),
+        existing_nullable=False,
+        server_default="main",
+    )