Draft: Fix deadlock between DataNode createDataRegion and ConfigNode PipeTaskCoordinatorLock by delegating consensus pipe lifecycle to ConfigNode

[Pengzna]

NOTE: This PR is genereated by Claude, I proposed the entire plans and prompts and have carefully reviewed this PR.

Problem

When using IoTConsensusV2, cluster initialization may deadlock during DataRegion creation (e.g., for root.__audit), causing "After 30 times retry, the cluster can't work!".

Root cause: Circular dependency between DataNode and ConfigNode:

1. ConfigNode holds PipeTaskCoordinatorLock → **pushSinglePipeMeta** to DataNode (blocking)
   DataNodeInternalRPCServiceImpl.pushSinglePipeMeta
   → PipeTaskAgent.handleSinglePipeMetaChanges
   → PipeTaskAgent.createPipe
   → PipeDataNodeTaskBuilder.build
   → IoTDBDataRegionSource.customize
   → IoTDBDataRegionSource.login
   → SessionManager.login
   → DataNodeAuthUtils.recordPasswordHistory
   → Coordinator.executeForTreeModel (INSERT audit data)
   → ClusterPartitionFetcher.getOrCreateDataPartition
   → ConfigNodeClient.getOrCreateDataPartitionTable (sync RPC call ConfigNode)
   → SocketTimeoutException: Read timed out
2. DataNode's **createDataRegion** handler → PipeConsensusServerImpl constructor → synchronous createPipe RPC back to ConfigNode → blocked by the same lock → timeout
   ConfigNode. CreateRegionGroupsProcedure ->DataNodeRegionManager.createDataRegion (line 157)
   → PipeConsensus.createLocalPeer
   → PipeConsensusServerImpl. (line 124)
   → createConsensusPipes
   → ConsensusPipeDataNodeDispatcher.createPipe (line 66)
   → ConfigNodeClient.createPipe (sync RPC call ConfigNode)

Solution

Delegate all consensus pipe lifecycle management to ConfigNode, eliminating DN→CN synchronous pipe RPCs entirely.

ConfigNode side:

• AddRegionPeerProcedure: add CREATE_CONSENSUS_PIPES state — creates bidirectional pipes between new peer and existing peers before DO_ADD_REGION_PEER
• RemoveRegionPeerProcedure: add DROP_CONSENSUS_PIPES state — drops related pipes after DELETE_OLD_REGION_PEER
• RegionMaintainHandler: add helper methods to build TCreatePipeReq and invoke ProcedureManager.createConsensusPipe/dropConsensusPipe

DataNode side:

• PipeConsensusServerImpl: remove createConsensusPipes call from constructor (pipes are created by ConfigNode's procedure)
• ConsensusPipeDataNodeDispatcher: convert to no-op (all 4 methods just return immediately)

Consistency guarantees:

• New DataRegion creation: ConfigNode already creates pipes via CreatePipeProcedureV2
• Region migration: ConfigNode creates pipes deterministically in procedure before coordinator starts data transfer
• checkConsensusPipe guardian still detects inconsistencies via logging; peerManager updates are preserved through existing P2P notification flow