fix: ensure scenario summary artifact is written to CI path

[jverdicc]

Motivation

• Ensure the scenario summary artifact artifacts/scenarios/summary.json is produced at the repository root so the CI artifact existence check does not fail when running the scenario system test.

Description

• Update scripts/run_scenarios.sh to pass an absolute SCENARIO_ARTIFACT_DIR by setting SCENARIO_ARTIFACT_DIR="$(pwd)/artifacts/scenarios" when invoking cargo test -p evidenceos-daemon --test scenarios_system -- --nocapture so the test writes into the repo-level artifact directory.

Testing

• Ran bash scripts/run_scenarios.sh and confirmed artifacts/scenarios/summary.json exists and is non-empty, ran cargo fmt --all && cargo fmt --check, and ran cargo test --workspace with final verification showing FINAL:0.

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Codex Task