Add getSessionMetadata for O(1) session lookup by ID

[brunoborges]

Summary

Ports upstream copilot-sdk PR #899 to the Java SDK. Adds a new getSessionMetadata(String sessionId) method to CopilotClient that calls the session.getMetadata JSON-RPC endpoint for efficient O(1) single-session metadata lookup. Returns null when the session is not found (Java-idiomatic absent value).

Changes

• CopilotClient.java — New getSessionMetadata(String) method following the same pattern as listSessions/deleteSession
• GetSessionMetadataResponse.java — New response DTO record for the session.getMetadata RPC call
• SessionMetadata.java — Updated Javadoc to reference the new method
• CopilotSessionTest.java — New @Disabled E2E test matching the upstream skip pattern (needs test harness CAPI proxy support for session lifecycle tests)

Testing

• mvn verify passes: 463 tests run, 0 failures, 1 skipped (the new disabled test)
• Test follows the same structure as existing testShouldListSessions and testShouldDeleteSession

Upstream reference

SDK	Method	Return type	Not-found value
Java	getSessionMetadata(sessionId)	CompletableFuture<SessionMetadata>	null

[Copilot]

Pull request overview

Ports upstream support for O(1) session metadata lookup by adding a new CopilotClient#getSessionMetadata(String) API that calls the session.getMetadata JSON-RPC endpoint, plus the associated response DTO and test scaffolding.

Changes:

• Add CopilotClient#getSessionMetadata(String) that returns SessionMetadata (or null if not found).
• Introduce GetSessionMetadataResponse DTO for session.getMetadata RPC responses.
• Update SessionMetadata Javadoc and add a disabled E2E test for the new behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/main/java/com/github/copilot/sdk/CopilotClient.java	Adds the new getSessionMetadata JSON-RPC wrapper method.
src/main/java/com/github/copilot/sdk/json/GetSessionMetadataResponse.java	Adds the RPC response record used to deserialize session.getMetadata results.
src/main/java/com/github/copilot/sdk/json/SessionMetadata.java	Updates Javadoc to reference the new lookup API.
src/test/java/com/github/copilot/sdk/CopilotSessionTest.java	Adds an (currently disabled) E2E test for session metadata lookup by ID.

[Copilot]

The @since tag is set to 1.0.0, but this response type (and CopilotClient#getSessionMetadata(String)) is being introduced in this PR. Please update @since to the version where this API is actually added (consistent with other newer additions that use @since 1.2.0, etc.).

Suggested change

	* @since 1.0.0
	* @since 1.2.0

[edburns]

Converting this to draft until the reference implementation PR github/copilot-sdk#899 is merged. @MackinnonBuck is still actively working on this.