Add rewind support across all SDKs

[stephentoub]

copilot-agent-runtime now supports rewinding conversation history and tracked file changes, but SDK sessions must explicitly opt into file-change tracking. This change exposes that opt-in consistently across every supported SDK.

Summary

• Add the optional enableFileChangeTracking session setting to Node, Python, Go, .NET, Rust, and Java.
• Forward the setting through both session creation and resumption requests while preserving the existing omitted-by-default behavior.
• Extend request-shape and clone coverage for the new option.
• Add a shared replay scenario and language-native E2E tests that create a tracked file, list and preview the rewind point, rewind conversation and files, and verify the file and discarded events are removed.

Testing

Not run locally per request; validation is deferred to CI.

Generated by Copilot

[Copilot]

Pull request overview

Adds opt-in file-change tracking across all SDKs, enabling rewind operations to restore conversation history and modified files.

Changes:

• Exposes and forwards enableFileChangeTracking during session creation and resumption.
• Covers request serialization and configuration cloning.
• Adds a shared replay fixture and E2E coverage for file and conversation rewind.

Show a summary per file

File	Description
test/snapshots/rewind/should_restore_tracked_file_and_conversation.yaml	Adds the shared rewind replay scenario.
rust/tests/session_test.rs	Tests Rust request forwarding.
rust/tests/e2e/rewind.rs	Adds Rust rewind E2E coverage.
rust/tests/e2e.rs	Registers the Rust E2E module.
rust/src/wire.rs	Adds the option to Rust wire requests.
rust/src/types.rs	Exposes and forwards the Rust setting.
python/test_client.py	Tests Python request forwarding.
python/e2e/test_rewind_e2e.py	Adds Python rewind E2E coverage.
python/copilot/client.py	Exposes and forwards the Python option.
nodejs/test/e2e/rewind.e2e.test.ts	Adds Node.js rewind E2E coverage.
nodejs/test/client.test.ts	Tests Node.js request forwarding.
nodejs/src/types.ts	Adds the Node.js configuration property.
nodejs/src/client.ts	Forwards the Node.js setting.
java/src/test/java/com/github/copilot/SessionRequestBuilderTest.java	Tests Java request construction.
java/src/test/java/com/github/copilot/e2e/RewindIT.java	Adds Java rewind E2E coverage.
java/src/test/java/com/github/copilot/ConfigCloneTest.java	Tests Java configuration cloning.
java/src/main/java/com/github/copilot/SessionRequestBuilder.java	Forwards the Java setting.
java/src/main/java/com/github/copilot/rpc/SessionConfig.java	Adds Java create-session configuration.
java/src/main/java/com/github/copilot/rpc/ResumeSessionRequest.java	Adds the Java resume request field.
java/src/main/java/com/github/copilot/rpc/ResumeSessionConfig.java	Adds Java resume-session configuration.
java/src/main/java/com/github/copilot/rpc/CreateSessionRequest.java	Adds the Java create request field.
go/types.go	Adds Go configuration and wire fields.
go/internal/e2e/rewind_e2e_test.go	Adds Go rewind E2E coverage.
go/client.go	Forwards the Go setting.
go/client_test.go	Tests Go request forwarding.
dotnet/test/Unit/SerializationTests.cs	Tests .NET request serialization.
dotnet/test/Unit/CloneTests.cs	Tests .NET configuration cloning.
dotnet/test/E2E/RewindE2ETests.cs	Adds .NET rewind E2E coverage.
dotnet/src/Types.cs	Exposes and clones the .NET option.
dotnet/src/Client.cs	Forwards the .NET setting in requests.

Review details

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• Files reviewed: 30/30 changed files
• Comments generated: 0
• Review effort level: Balanced

[github-actions]

Cross-SDK Consistency Review ✅

This PR adds enableFileChangeTracking to all six SDK implementations consistently:

SDK	Property Name	Convention
Node.js/TypeScript	enableFileChangeTracking	camelCase ✅
Python	enable_file_change_tracking	snake_case ✅
Go	EnableFileChangeTracking	PascalCase ✅
.NET	EnableFileChangeTracking	PascalCase ✅
Java	enableFileChangeTracking (via getEnableFileChangeTracking())	camelCase ✅
Rust	enable_file_change_tracking	snake_case ✅

All SDKs:

• Add the option to both session creation and resumption configs
• Use bool?/Option<bool>/*bool (nullable/optional) with omit-by-default behavior
• Include E2E tests against the shared replay snapshot
• Forward the field through the wire protocol as enableFileChangeTracking

No consistency issues found. The PR maintains full cross-SDK parity.

Generated by SDK Consistency Review Agent for #2321 · sonnet46 28.7 AIC · ⌖ 5.39 AIC · ⊞ 6.6K · ◷