* Update IAM and S3 protobuf definitions for explicit IAM gRPC APIs
* Refactor s3api: Extract generic ExecuteAction method for IAM operations
* Implement explicit IAM gRPC APIs in S3 server
* iam: remove deprecated GetConfiguration and PutConfiguration RPCs
* iamapi: refactor handlers to use CredentialManager directly
* s3api: refactor embedded IAM to use CredentialManager directly
* server: remove deprecated configuration gRPC handlers
* credential/grpc: refactor configuration calls to return error
* shell: update s3.configure to list users instead of full config
* s3api: fix CreateServiceAccount gRPC handler to map required fields
* s3api: fix UpdateServiceAccount gRPC handler to map fields and safe status
* s3api: enforce UserName in embedded IAM ListAccessKeys
* test: fix test_config.json structure to match proto definition
* Revert "credential/grpc: refactor configuration calls to return error"
This reverts commit cde707dd8b88c7d1bd730271518542eceb5ed069.
* Revert "server: remove deprecated configuration gRPC handlers"
This reverts commit 7307e205a083c8315cf84ddc2614b3e50eda2e33.
* Revert "s3api: enforce UserName in embedded IAM ListAccessKeys"
This reverts commit adf727ba52b4f3ffb911f0d0df85db858412ff83.
* Revert "s3api: fix UpdateServiceAccount gRPC handler to map fields and safe status"
This reverts commit 6a4be3314d43b6c8fda8d5e0558e83e87a19df3f.
* Revert "s3api: fix CreateServiceAccount gRPC handler to map required fields"
This reverts commit 9bb4425f07fbad38fb68d33e5c0aa573d8912a37.
* Revert "shell: update s3.configure to list users instead of full config"
This reverts commit f3304ead537b3e6be03d46df4cb55983ab931726.
* Revert "s3api: refactor embedded IAM to use CredentialManager directly"
This reverts commit 9012f27af82d11f0e824877712a5ae2505a65f86.
* Revert "iamapi: refactor handlers to use CredentialManager directly"
This reverts commit 3a148212236576b0a3aa4d991c2abb014fb46091.
* Revert "iam: remove deprecated GetConfiguration and PutConfiguration RPCs"
This reverts commit e16e08aa0099699338d3155bc7428e1051ce0a6a.
* s3api: address IAM code review comments (error handling, logging, gRPC response mapping)
* s3api: add robustness to startup by retrying KEK and IAM config loading from Filer
* s3api: address IAM gRPC code review comments (safety, validation, status logic)
* fix return
43229b05ce