feat(backup): 新增 CDC 内容寻址仓库模式

使用内容定义分块、不可变 pack 与快照索引实现跨文件和跨快照去重。

接入多目标上传、软配额、恢复、下载、校验、保留和安全垃圾回收，并补充前端入口、中英文文档及端到端测试。

Closes #94

web/src/components/backup-tasks/BackupTaskFormDrawer.tsx

@@ -251,6 +251,12 @@ export function BackupTaskFormDrawer({ visible, loading, initialValue, storageTa
       if (validPaths.length === 0 && !value.sourcePath.trim()) {
         return '请输入至少一个源路径'
       }
+      if (value.backupMode === 'repository' && (((value.nodeId ?? 0) > 0 && value.nodeId !== localNodeId) || value.nodePoolTag?.trim())) {
+        return 'CDC 仓库模式当前仅支持 Master 本机执行'
+      }
+      if (value.backupMode === 'repository' && value.replicationTargetIds.length > 0) {
+        return 'CDC 仓库模式请直接多选存储目标，不能使用对象级副本复制'
+      }
     }
     if (isSQLiteBackupTask(value.type) && !value.dbPath.trim()) {
       return '请输入 SQLite 数据库路径'
@@ -314,7 +320,13 @@ export function BackupTaskFormDrawer({ visible, loading, initialValue, storageTa
             onChange={(value) => {
               const nodeId = Number(value ?? 0)
               // 固定节点与节点池互斥：切到固定节点时清空 NodePoolTag
-              updateDraft(nodeId > 0 ? { nodeId, nodePoolTag: '' } : { nodeId })
+              updateDraft(nodeId > 0
+                ? {
+                  nodeId,
+                  nodePoolTag: '',
+                  backupMode: nodeId !== localNodeId && draft.backupMode === 'repository' ? 'full' : draft.backupMode,
+                }
+                : { nodeId })
             }}
           />
           <Typography.Paragraph type="secondary" style={{ marginBottom: 0, marginTop: 4 }}>
@@ -327,7 +339,10 @@ export function BackupTaskFormDrawer({ visible, loading, initialValue, storageTa
             placeholder="填写标签后从节点池动态调度（与固定节点互斥）"
             value={draft.nodePoolTag ?? ''}
             disabled={(draft.nodeId ?? 0) > 0}
-            onChange={(value) => updateDraft({ nodePoolTag: value })}
+            onChange={(value) => updateDraft({
+              nodePoolTag: value,
+              backupMode: value.trim() && draft.backupMode === 'repository' ? 'full' : draft.backupMode,
+            })}
           />
           <Typography.Paragraph type="secondary" style={{ marginBottom: 0, marginTop: 4 }}>
             执行节点选"本机 / 未指定"时可启用；从节点 Labels 命中此 tag 的在线节点中按当前运行任务数最少的挑选一台执行。
@@ -600,8 +615,11 @@ export function BackupTaskFormDrawer({ visible, loading, initialValue, storageTa
               options={[
                 { label: '全量备份', value: 'full' },
                 { label: '差异备份（仅文件、本机）', value: 'differential' },
+                { label: 'CDC 去重仓库（仅文件、本机）', value: 'repository' },
               ]}
-              onChange={(value) => updateDraft({ backupMode: value as BackupMode })}
+              onChange={(value) => updateDraft(value === 'repository'
+                ? { backupMode: value as BackupMode, nodeId: 0, nodePoolTag: '', replicationTargetIds: [] }
+                : { backupMode: value as BackupMode })}
             />
             {draft.backupMode === 'differential' && (
               <div style={{ marginTop: 8 }}>
@@ -618,6 +636,11 @@ export function BackupTaskFormDrawer({ visible, loading, initialValue, storageTa
                 />
               </div>
             )}
+            {draft.backupMode === 'repository' && (
+              <Typography.Paragraph type="secondary" style={{ marginBottom: 0, marginTop: 8 }}>
+                文件按内容边界切块并写入全局分块池；相同数据跨文件、跨快照只上传一次。新块会合并为 pack，恢复时通过索引按需读取。当前版本采用单写者索引，因此固定在 Master 本机执行；需要多副本时请直接多选上方存储目标。
+              </Typography.Paragraph>
+            )}
           </div>
         )}
         <div>
@@ -736,10 +759,13 @@ export function BackupTaskFormDrawer({ visible, loading, initialValue, storageTa
             value={draft.replicationTargetIds}
             placeholder="选择副本目标（不选 = 不启用复制）"
             options={storageTargetOptions.filter((opt) => !(draft.storageTargetIds ?? []).includes(opt.value as number))}
+            disabled={draft.backupMode === 'repository'}
             onChange={(values: number[]) => updateDraft({ replicationTargetIds: values })}
           />
           <Typography.Paragraph type="secondary" style={{ marginBottom: 0, marginTop: 4 }}>
-            备份成功后自动镜像到副本存储。满足 3-2-1 规则：至少 2 份副本、至少 1 份异地。建议选不同 provider 的目标。
+            {draft.backupMode === 'repository'
+              ? 'CDC 仓库包含共享 pack 与索引，不能只复制单个快照对象；请在“存储目标”中直接多选以生成完整仓库副本。'
+              : '备份成功后自动镜像到副本存储。满足 3-2-1 规则：至少 2 份副本、至少 1 份异地。建议选不同 provider 的目标。'}
           </Typography.Paragraph>
         </div>
 

web/src/pages/backup-records/BackupRecordsPage.tsx

@@ -114,6 +114,7 @@ export function BackupRecordsPage() {
             <Typography.Text>{record.fileName || '-'}</Typography.Text>
             {record.locked && <Tag color="orange" size="small" bordered>已锁定</Tag>}
             {record.backupKind === 'differential' && <Tag color="purple" size="small" bordered>差异</Tag>}
+            {record.backupKind === 'repository' && <Tag color="blue" size="small" bordered>CDC</Tag>}
           </Space>
           <Typography.Text type="secondary">{formatBytes(record.fileSize)}</Typography.Text>
           {record.checksum && (

web/src/types/backup-records.ts

@@ -26,7 +26,7 @@ export interface BackupRecordSummary {
   startedAt: string
   completedAt?: string
   locked: boolean
-  backupKind: 'full' | 'differential'
+  backupKind: 'full' | 'differential' | 'repository'
 }
 
 export interface BackupRecordContentEntry {

web/src/types/backup-tasks.ts

@@ -1,7 +1,7 @@
 export type BackupTaskType = 'file' | 'mysql' | 'sqlite' | 'postgresql' | 'saphana' | 'mongodb'
 export type BackupTaskStatus = 'idle' | 'running' | 'success' | 'failed'
 export type BackupCompression = 'gzip' | 'zstd' | 'none'
-export type BackupMode = 'full' | 'differential'
+export type BackupMode = 'full' | 'differential' | 'repository'
 
 export interface BackupTaskSummary {
   id: number