The workspace denies `clippy::expect_used` in production. Although
`clippy.toml` allows `expect` in tests, Bazel Clippy compiles
integration-test helper code in a way that does not receive that
exemption, which encouraged verbose `unwrap_or_else(... panic!(...))`
and equivalent `match`/`let else` forms.
This allows `clippy::expect_used` once at each integration-test crate
root (including aggregated suites and test-support libraries), then
replaces manual panic-based Result and Option unwraps with
`expect`/`expect_err`. Standalone `tests/*.rs` files remain their own
crate roots. Intentional assertion and unexpected-variant panics remain
unchanged, and the production `expect_used = "deny"` lint remains in
place.
The cleanup is mechanical and net-negative in line count.
## Why
Exec-server request and connection latencies need fractional-second
histograms. The existing duration API records integer milliseconds and
uses millisecond-scale buckets.
## What changed
- Adds a described duration API that records `Duration` values as
fractional seconds.
- Uses second-scale explicit histogram boundaries.
- Caches duration histograms by name, unit, and description, matching
the existing instrument caching model.
- Covers exact boundaries, representative bucket placement, fractional
sums, and exported metadata.
This PR only adds the duration primitive. It does not add exec-server
adoption.
## Stack
1. #26091: counter descriptions
2. #27057: gauge instruments
3. **#27058: second-based duration histograms**
4. #25019: initialize exec-server OpenTelemetry at startup
Related independent coverage: #27059 tests OTLP HTTP log and trace event
export.
## Validation
- `just test -p codex-otel`
## Summary
- reduce public module visibility across Rust crates, preferring private
or crate-private modules with explicit crate-root public exports
- update external call sites and tests to use the intended public crate
APIs instead of reaching through module trees
- add the module visibility guideline to AGENTS.md
## Validation
- `cargo check --workspace --all-targets --message-format=short` passed
before the final fix/format pass
- `just fix` completed successfully
- `just fmt` completed successfully
- `git diff --check` passed
Add metrics capabilities to Codex. The `README.md` is up to date.
This will not be merged with the metrics before this PR of course:
https://github.com/openai/codex/pull/8350
