Stabilize asynchronous telemetry flush test

[enaboapps]

Summary

• replace a fixed 30 ms sleep with a bounded wait for the asynchronous telemetry flush to finish
• keep the change entirely in test code; production telemetry behavior and interfaces are unchanged

Root cause

The Alpha 4 release PR's Windows CI failed twice because the hosted runner could still be flushing when the test read persisted state. The assertion raced the runtime scheduler rather than the service contract.

Validation

• focused failing test passed 20 consecutive runs

pm run lint

pm test

pm run build

• cargo fmt --manifest-path src-tauri/Cargo.toml --check
• cargo clippy --manifest-path src-tauri/Cargo.toml --all-targets -- -D warnings
• cargo test --manifest-path src-tauri/Cargo.toml (133 passed)

Closes #572

[greptile-apps]

Greptile Summary

The telemetry test now uses bounded polling to wait for the expected retry persistence and successful queue drain before checking the stored telemetry state.

Confidence Score: 5/5

No blocking failure remains.

The current completion conditions wait for the required queue, send, and persistence states before assertions inspect the resulting telemetry data.

T-Rex Logs

What T-Rex did

• T-Rex attempted the focused Cargo test for failed_reports_queue_flush_and_keep_a_stable_opaque_id, but native compilation stopped due to missing gdk-3.0.pc.
• T-Rex compiled and ran a focused Rust scheduling model covering completion handoff, successor acknowledgement, and final persistence ordering, and all three checks passed.
• T-Rex captured and uploaded validation evidence, including the authored Rust source and observed output, and verified that the model reported PASS for the three checks.
• T-Rex noted the native validation blocker: the gdk-3.0.pc file is unavailable and PKG_CONFIG_PATH is unset.

_{Ran code and verified through T-Rex}

_{Reviews (4): Last reviewed commit: "Verify persisted retry state" | Re-trigger Greptile}