[jbeda]

Summary

Fix two terminal-client test flakes as a small test-only batch:

• Fixes flake: TestQueuedPromptAutoSendsProgram sometimes sends only the first prompt #2580: wait for both actual prompt frames to be recorded before the queued-prompt program test shuts down. Run completion is not a join barrier for Bubble Tea's asynchronous send commands.
• Fixes flake: TestConverseRejectedWithAFailedRefresh intermittently fails sending prompt with EOF #2582: tolerate gRPC send-side EOF in the Converse test helper and keep reading the authoritative stream status. Preserve auth-reason assertions and additionally verify exactly one forced refresh, one Converse attempt, and no handler-received prompts.
• Add a deterministic failed-refresh-before-send regression for issuer-unavailable, session-expired, and unknown refresh errors. Restoring the old strict send check makes all three cases fail with send prompt: EOF.

No production changes, sleeps, retries, or timeout increases.

Verification

• task test
• task test:race
• task lint
• go run ./cmd/mecademo — tool call, permission ask/approval, and final result verified
• go test -race ./cmd/mecatui/client -run 'Test(Converse|StreamReplaysAFrameSentAfterTheRejection)' -count=100 -cpu=1,2,4 -timeout=5m
• go test -race ./cmd/mecatui/ui -run '^TestQueuedPromptAutoSendsProgram$' -count=100 -cpu=1,2,4 -timeout=5m
• Mutation check: restoring strict send-error handling fails every deterministic failed-refresh regression case; restoring the fix passes.
• Four-axis review: no blockers or important findings. One advisory notes that the deterministic auth regression uses a fake transport, supplemented by existing real-gRPC integration coverage.

API compatibility

No wire, Go production API, or stored-data changes. Only test fixtures, synchronization, and assertions change; API major and feature identifiers are unchanged, and no client/server upgrade coordination is required.