refactor(pd): merge cse-pd into pd repository

[bufferflies]

Summary

Track the release-8.5-keyspace commit batch that has been split into 41 subtasks by functional area.

Branch

• target branch: release-8.5-keyspace
• origin repo: bufferflies/pd

Scope

mTLS / pd-ctl

• pd-ctl: add show region by keyspace-id and table-id - PR: #10519 #10531
• ac5b0db3 mtls: batch cherry-pick mTLS changes from release-7.5-keyspace #10561
• dc3b174c support providing cert paths by environment variables #10532

Keyspace / GC

• 0c88ce89 add option to skip rawkv region bound #10534
• ad8acf86 async create pre-alloc keyspaces #10566
• 78f39c6d support new keyspace enable gc v2
• 6326f2d5 fix global service safe point
• f88a4fd9 fix enable-global-safe-point-v2 init
• 76277a6b create keyspace metrics and logs

Meta Service Group

• 45bc455d support etcd groups #10596
• 0b70d5de change add method to patch
• e1d53f36 add switch for auto assign keyspace to meta service group
• 5be7eae7 add meta-service-group status
• d473bf9d add meta service group fallback ratio
• 60279efd unassign keyspace from meta service group when setting tombstone
• 2baf2a50 cache meta-service group status

API / Observability

• 4b4ac9b5 add safe point HTTP API v2
• a7c733be add PD API metrics and logs - PR: #10523

Resource Manager / RU

• 04affc41 push RU metrics to metering server
• ff840e15 redirect resource manager requests to resource manager service
• d22a5677 add resource manager fallback config
• 6e895856 fix resource manager API redirector
• a6b85376 add RCU tracker and record consume rate
• 71e81850 only record active resource group metrics
• 467deb4f only persist states of active resource groups
• da1b8ba1 implement async loading for resource groups
• 767c4d30 modify resource_manager_resource_unit_service_limit metric
• 627dc6ed check and add log

Client / Service Discovery

• 70e5fb6f resource manager service discovery #10537
• c300ffdf update resource manager service URL after error #10538
• 6e2a4d20 add backoff mechanism for service URL updates #10539

Client / Resource Group

• 3405eeea return a specified resource group when get resource group fails #10557
• c3cd07c6 remove meta revision #10542

TSO / Keyspace Group

• 7ba9d7e9 fix split operation fallback to group 0
• 407ad06f support removing archive and tombstone keyspaces from keyspace group #10555
• 7786830e fix TSO service fallback group 0 return #10554
• 271ac93b add TSO fallback metrics
• 2d9d3fd5 sort old keyspace in updateKeyspaceGroupMembership #10533

TSO / Client

• d0535999 do not fallback to group 0 when no TSO service is available #10553
• 88e4f7d1 validate callee ID for TSO requests #10552

Notes

• Internal execution was split into one parent task plus 41 per-commit subtasks.
• This issue is the umbrella tracker for the full release-8.5-keyspace batch.
• Initial audit against origin/master on 2026-03-31 found no patch-equivalent fixes for these 41 commits, so all tasks remain open.