Fix Oracle test shutdown hangs and speed up CI setup

[lovasoa]

The Oracle job passed all 89 integration tests in 25 seconds, then hung until the five-minute timeout. Reproducing its artifact in Ubuntu 24.04 showed the process blocked in Oracle’s finiSqora → bccFreeProcess → SltsPrWrite destructor with database sessions still open. Serial test execution also hung.

Use a shared integration-test runtime that clears prepared-statement caches and awaits pool closure before shutting down, including when a test panics. Route application-state construction through the tracked fixture and add a success/panic teardown regression test. Oracle CI also caps harness concurrency at two threads to avoid ORA-12516 listener exhaustion on larger runners; the concurrent-request test retains its existing workload.

Replace RPM-to-Debian conversion with SHA-256-verified, cached ZIP archives of the same Oracle 21.21 client. Register the driver and libaio compatibility link in the runner’s temporary directory. Warm installation took about 1.4 seconds locally.

Validation:

• cargo fmt --all and formatting check
• cargo clippy --all-targets --all-features -- -D warnings
• cargo test: 235 unit tests and 90 integration tests passed
• Three consecutive Ubuntu 24.04 Oracle integration runs with static unixODBC and CI allocator settings: all 90 tests passed and each process exited normally (16–22 seconds)
• Complete packaged Oracle run in Ubuntu 24.04 using the named driver: 235 unit tests and 90 integration tests passed; all harnesses exited normally
• ShellCheck, Bash syntax, CI YAML/matrix checks, and rejection of corrupted cached archives

No production behavior changes or test exclusions are added. Other database backends are left to the existing CI matrix.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-04T21:41:52.944993Z	4621ed3	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.