[WIP] Sync upstream changes with 28 new commits

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[upstream-sync] Upstream sync: 28 new commits (2026-03-02)</issue_title>
<issue_description>## Upstream Changes Detected

Commit Range: f0909a7...b9f746a
Number of commits: 28

Recent Commits (most recent first)

• b9f746a fix(python): correct PermissionHandler.approve_all type annotations (#618)
• bb02de1 [C#] Use event delegate for thread-safe, insertion-ordered event handler dispatch (#624)
• 7cc50b6 fix Justfile doesn't install everything necessary to run the test suite (#611)
• 5718e12 [Python] Remove --locked flag from uv sync in copilot-setup-steps.yml (#628)
• 6415c40 [C#] Remove unnecessary SemaphoreSlim locks for handler fields (#625)
• cb94df9 [C#] Deduplicate OnDisposeCall and improve implementation (#626)
• 47cb899 Update @github/copilot to 0.0.420 (#605)
• 58455ec Add workflow to update @github/copilot dependency (#604)
• 117eaf8 Have CopilotClient.stop() raise an exception group instead of returning a list of exceptions (#603)
• d87af41 Restore package discovery for platform wheel builds (#601)
• 9d942d4 feat(docs-validation): add hidden block directive and convert samples (#600)
• fc63890 docs: fix OpenTelemetry guide to use correct SDK APIs (#597)
• 942a253 docs: Add OpenTelemetry instrumentation guide for Copilot SDK (#529)
• 23a9134 fix(python): use 'is not None' check for excluded_tools in session methods (#596)
• 8e61e9b More e2e nodejs tests (#466)
• 0e46b36 chore(deps): bump minimatch (#594)
• 4612a15 chore(deps-dev): bump hono (#595)
• 9170468 chore(deps-dev): bump minimatch (#593)
• 35534c4 chore(python): Bump the oldest supported Python version to 3.11 (#561)
• 5a4f823 Fix Go client data races (#586)

Instructions

Please follow the agentic-merge-upstream prompt to port these changes to the Java SDK.

Important: When creating the Pull Request, add the upstream-sync label to allow tracking of the merge progress.

AI generated by Weekly Upstream Sync Agentic Workflow

• expires on Mar 8, 2026, 9:56 PM UTC

Comments on the Issue (you are @copilot in this section)

• Fixes [upstream-sync] Upstream sync: 28 new commits (2026-03-02) #153

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