refactor: standardize fmt imports and restore submodule separation in proto_ext

[drmingdrmer]

Changelog

refactor: standardize fmt imports and restore submodule separation in proto_ext

• Use use std::fmt; with fmt::Display/fmt::Formatter instead of importing individual types
• Restore Display impls to separate submodule files (txn_op_ext/request_ext, txn_op_response_ext/response_ext, txn_condition_ext/condition_result_ext, txn_condition_ext/target_ext)
• Split raft_types_ext into vote_ext and log_id_ext submodules

feat: add missing constructors and tests for proto_ext types

Several protobuf extension types had API gaps: TxnDeleteByPrefixRequest,
TxnDeleteResponse, and TxnDeleteByPrefixResponse lacked new() constructors
that their sibling types already had. TxnOp had convenience constructors for
every Request variant except DeleteByPrefix, forcing callers to build the
struct manually.

Changes:

• Add TxnDeleteByPrefixRequest::new(), TxnDeleteResponse::new(),
  TxnDeleteByPrefixResponse::new() constructors
• Add TxnOp::delete_by_prefix() to match other TxnOp variant constructors
• Add test modules to 11 files that had zero test coverage: raft type
  round-trips, txn request/response constructors and Display impls, and
  TxnCondition::Target Display variants

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• Improvement

[xp-trumpet]

@xp-trumpet reviewed 24 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @drmingdrmer).

[Copilot]

Pull request overview

This PR refactors the proto_ext module to standardize fmt imports and improve code organization. It changes all files to use use std::fmt; with qualified types instead of importing individual Display/Formatter types. The PR also splits larger modules into submodules (raft_types_ext into vote_ext and log_id_ext) and adds missing constructors and test coverage for several proto types.

Changes:

• Standardized fmt imports across all proto_ext files to use use std::fmt; pattern
• Reorganized module structure: split raft_types_ext into vote_ext and log_id_ext submodules, restored Display impls to separate submodule files
• Added missing new() constructors for TxnDeleteByPrefixRequest, TxnDeleteResponse, TxnDeleteByPrefixResponse, and TxnOp::delete_by_prefix()
• Added comprehensive test coverage (11 files that previously had zero tests)

Reviewed changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
txn_request_ext.rs	Standardized fmt imports
txn_reply_ext.rs	Standardized fmt imports
txn_put_response_ext.rs	Standardized fmt imports, added tests for Display and unpack methods
txn_put_request_ext.rs	Standardized fmt imports, added tests for new() and Display
txn_op_response_ext/response_ext.rs	Standardized fmt imports, moved test to parent module, simplified Display match arms
txn_op_response_ext.rs	Added test_response_from test (moved from submodule)
txn_op_ext/request_ext.rs	Standardized fmt imports, simplified Display match arms
txn_op_ext.rs	Added delete_by_prefix() constructor and test
txn_delete_response_ext.rs	Standardized fmt imports, added new() constructor and tests
txn_delete_request_ext.rs	Standardized fmt imports, added tests for new() and Display
txn_delete_by_prefix_response_ext.rs	Standardized fmt imports, added new() constructor and tests
txn_delete_by_prefix_request_ext.rs	Standardized fmt imports, added new() constructor and tests
txn_condition_ext/target_ext.rs	Standardized fmt imports, simplified Display match arms, added Display tests
txn_condition_ext/condition_result_ext.rs	Standardized fmt imports
txn_condition_ext.rs	Standardized fmt imports
raft_types_ext/vote_ext.rs	New file: Vote conversion implementations with round-trip tests
raft_types_ext/log_id_ext.rs	New file: LogId conversion implementations with round-trip test
raft_types_ext.rs	Split into vote_ext and log_id_ext submodules
mod.rs	Alphabetically sorted module imports
vote_response_ext.rs	Added round-trip tests for granted and rejected responses
vote_request_ext.rs	Added round-trip tests with and without log_id
keys_count_ext.rs	Added tests for new() and Display
fetch_increase_u64_response_ext.rs	Standardized fmt imports
boolean_expression_ext.rs	Standardized fmt imports

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[Copilot]

The delete_by_prefix constructor should use pb::TxnDeleteByPrefixRequest::new(prefix) instead of constructing the struct inline, to be consistent with other constructors in this file like delete_exact (line 85-86) and get (line 94) which use the .new() method.

Suggested change

	pb::TxnDeleteByPrefixRequest {
	prefix: prefix.to_string(),
	},
	pb::TxnDeleteByPrefixRequest::new(prefix),