feat: add ability to gracefully stop runs

[thedadams]

Various parts of a tool execution cannot be stopped gracefully. For example,
non-streamed HTTP request can't be stopped gracefully. However, commands and
chat completions can be gracefully stopped by a user and the result returned.
An "ABORTED BY USER" message is added to such messages. Additionally, aborted
chat completion responses are not stored in the cache.

Signed-off-by: Donnie Adams [email protected]

[Copilot]

Copilot reviewed 26 out of 26 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (4)

pkg/sdkserver/routes.go:96

• Breaking out of the event loop on receiving a run-finish event may leave subsequent events unprocessed. Consider ensuring that remaining events are either drained or that the behavior is properly documented.

if e.Type == runner.EventTypeRunFinish { break }

pkg/openai/client.go:606

• [nitpick] Cancellation errors are being suppressed by setting err to nil when context.Canceled is detected. Verify that this behavior is intended so that genuine errors are not inadvertently hidden.

if errors.Is(err, context.Canceled) { err = nil }

pkg/engine/openapi.go:148

• The update from using the ptr helper (i.e. ptr(result)) to directly taking the address of result should be reviewed to ensure it remains consistent with other parts of the code and preserves the intended behavior.

Result: &result,

pkg/runner/runner.go:674

• [nitpick] The removal of the explicit copy of subCall.State (previously done via subState := *subCall.State) in favor of directly using WithResumeInput may introduce side effects related to state mutability. Confirm that this change correctly propagates the resume input without unintended modifications.

result, err := r.subCallResume(callCtx.Ctx, callCtx, monitor, env, subCall.ToolID, subCall.CallID, subCall.State.WithResumeInput(state.ResumeInput), toolCategory)