Upstream sync: serialize event dispatch, skipPermission, TelemetryConfig, reasoningEffort (2026-03-17)

[Copilot]

Ports 19 upstream commits (062b61c→485ea5e) from github/copilot-sdk. Key behavioral changes and new APIs below.

Serialized event dispatch (b100339)

Events are now queued and delivered serially on a dedicated background thread (copilot-session-events) instead of inline on the JSON-RPC reader thread. This prevents deadlocks when close() is called from within a handler and ensures handlers are never invoked concurrently.

skipPermission on ToolDefinition (10c4d02)

Tools can now opt out of the permission prompt entirely:

ToolDefinition.createSkipPermission("safe_lookup", "...", schema, handler)

The skipPermission field is serialized to the CLI in the tool registration payload.

no-result permission kind (df59a0e)

PermissionRequestResultKind.NO_RESULT added. Returning this from a v3 broadcast permission handler silently skips responding to the pending request (allows another client to handle it).

setModel with reasoningEffort (ea90f07)

session.setModel("claude-sonnet-4.6", "high").get();

SessionModelChangeEvent also gains reasoningEffort and previousReasoningEffort fields.

TelemetryConfig + OpenTelemetry CLI support (f2d21a0)

new CopilotClientOptions().setTelemetry(new TelemetryConfig()
    .setOtlpEndpoint("http://localhost:4317")
    .setExporterType("otlp-http"));

Sets COPILOT_OTEL_ENABLED and related env vars on the CLI process.

autoRestart deprecated (5a41532)

CopilotClientOptions.setAutoRestart(boolean) is now @Deprecated — the option has no effect.

Other

• ExternalToolRequestedEvent gains traceparent/tracestate fields for OTel context propagation from CLI spans.
• .lastmerge updated to 485ea5e.

Pull request checklist

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• mvn spotless:apply has been run to format the code
• mvn clean verify passes locally

Does this introduce a breaking change?

• Yes
• No

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