Root cause of the failing CI run was that examples/tests referencing
feature-gated items were auto-detected (no required-features), so
`--all-targets` compiled them under feature combinations where those
modules didn't exist. Fixes:
- mytheclipse Cargo.toml: declare the `high_level` example and
`race_stress` integration test with required-features = ["full"];
`cargo build --all-targets` now skips them when full is off. This
clears the whole test-matrix (workspace default, all-features, and
every single-feature config) which all failed on E0432/E0433.
- lib.rs: auto_metrics_service depends on service_builder, so regate it
behind all(observability, resiliency) instead of observability alone
(observability-only build compiled the module without resiliency).
- mytheclipse-tracing: gate `pub mod fmt` behind any
tracing-subscriber-providing feature so --no-default-features compiles.
- mytheclipse-queue: gate `pub mod worker` behind in-memory (worker.rs
requires tokio, only provided by in-memory).
- clippy -D warnings fixes: deprecated base64 0.22 free fns -> Engine
(paseto), unused key field, needless mut (service_builder), unused
import/dead var/missing is_empty (bg_join), dead is_expired (dlock),
while-let-iterator->for (parallel_map), type_complexity (shutdown_guard),
MutexGuard held across await (middleware, now clones Arc'd layers),
if-let-Err->is_err (queue), unused CliBuilder fields now wired into clap.
- rustdoc -D warnings: resolve retry/MetricsBridge/CircuitBreaker/KeyRing
intra-doc links and fix the unparseable lifecycle.rs code fence.
- cargo fmt --all to satisfy the Rustfmt gate.
asepharyana