feat: Instant rename

[efirs]

No description provided.

[Copilot]

Pull Request Overview

This PR implements a new “instant rename” feature using Tigris, refactoring the rename flows and adding test cases to validate the new behavior. Key changes include:

• Introducing specialized rename functions (sendRenameSpecial, finishErrorSendRenameSpecial, finishSuccessSendRenameSpecial) and refactoring the legacy rename method.
• Adding new test scripts and updating flag configurations to support and control the Tigris rename functionality.
• Minor adjustments in logger output and S3 backend rename behavior to integrate the new feature.

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
test/run-cases.sh	Updated rename commands and added proxy run setup.
test/cases/tigris_rename.sh	New test cases for Tigris-based instant rename scenarios.
main.go	Minor update to log output formatting.
log/logger.go	Logger output now derived from a passed writer instead of os.Stdout.
core/tigris_test.go	Renamed functions to reflect test-specific Tigris detection.
core/goofys_common_test.go	Updated Tigris detection function calls to match renamed methods.
core/file.go	Refactored rename logic to split instant rename flow with better error handling.
core/cfg/logger.go	Updated logger configuration for syslog compatibility.
core/cfg/flags.go	Removed legacy Tigris flags and added new, inverted flags for rename and prefetch.
core/cfg/config.go	Added new TigrisRename flag and IsTigris endpoint detection logic.
core/backend_s3.go	Implemented S3 backend support for Tigris rename via a copy-object operation.
core/backend.go	Updated Capabilities struct with the new IsTigris flag.
core/aws_test.go	Adjusted tests to use updated Tigris detection functions.

Comments suppressed due to low confidence (2)

core/file.go:777

• The local variable 'oldParent' shadows the function parameter 'oldParent'. Consider renaming the local variable or using the parameter directly to avoid potential confusion.

oldParent := inode.oldParent

core/file.go:778

• The local variable 'oldName' shadows the function parameter 'oldName'. Renaming it or using the parameter would improve clarity and prevent unintended behavior.

oldName := inode.oldName