[reference-impl-sync] Reference Implementation sync: 4 new commits (2026-05-12)

[github-actions]

Automated Reference Implementation Sync

There are 4 new commits in the official Copilot SDK since the last merge.

• Last merged commit: 4a0437bb03a0b60a1867f14ae8e3faf053afa5aa
• Reference Implementation HEAD: e0a0f5e2f9fa153e4571ad42764e608a378a69fb

Recent reference implementation commits

e0a0f5e Use z-prefixed Go generated files (#1268)
f48afda Generate typed Go union interfaces (#1252)
7e7dac2 Update `@github/copilot` to 1.0.45 (#1263)
9915343 Fix C# listFiles E2E ordering assumption (#1261)

Instructions

You MUST follow these steps in order. Do NOT improvise or skip scripts.

1. ✅✅Read .github/prompts/agentic-merge-reference-impl.prompt.md in full before starting✅✅

❌❌Do NOT clone the reference implementation manually — the start script does this.❌❌
❌❌Do NOT update .lastmerge manually — the finish script does this.❌❌
❌❌Do NOT skip the finish script — it syncs codegen versions and updates .lastmerge.❌❌

Generated by Reference Implementation Sync · ● 213.2K · ◷

• expires on May 18, 2026, 4:58 PM UTC