立项配置版本管理优化（回滚逻辑、UI、下载功能）

backend/app/schemas/study_setup_config.py

@@ -92,14 +92,36 @@ class StudySetupConfigRollback(BaseModel):
     target_version: int
 
 
+class StudySetupConfigCheckoutBranch(BaseModel):
+    expected_version: int | None = None
+    target_version: int
+
+
+class StudySetupConfigDraftAction(BaseModel):
+    expected_version: int | None = None
+
+
+class StudySetupConfigMergeToMain(BaseModel):
+    expected_version: int | None = None
+    source_version: int
+
+
 class StudySetupConfigVersionRead(BaseModel):
     id: uuid.UUID
     study_id: uuid.UUID
     study_setup_config_id: uuid.UUID
     version: int
     display_version: int
+    branch_name: str = "main"
+    branch_seq: int = 1
+    version_label: str = ""
     source_version: int | None = None
+    parent_version_id: uuid.UUID | None = None
+    merged_from_version_id: uuid.UUID | None = None
     config: StudySetupConfigData
+    published_project_snapshot: "ProjectPublishSnapshot | None" = None
+    is_current_published: bool = False
+    is_active_draft_base: bool = False
     published_by: uuid.UUID | None = None
     published_by_name: str | None = None
     published_at: datetime
@@ -153,6 +175,11 @@ class StudySetupConfigRead(BaseModel):
     id: uuid.UUID
     study_id: uuid.UUID
     version: int
+    current_branch_name: str = "main"
+    current_published_version_id: uuid.UUID | None = None
+    current_published_version_label: str | None = None
+    active_branch_base_version_id: uuid.UUID | None = None
+    active_branch_base_version_label: str | None = None
     data: StudySetupConfigData
     publish_status: str
     published_data: StudySetupConfigData | None = None