fix(ci): restore full CI green — test-matrix, clippy, rustfmt, and rustdoc gates

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.

crates/mytheclipse-cli/src/builder.rs

@@ -1,6 +1,6 @@
 //! Clap-based CLI builder implementation.
 
-use clap::{Parser, Subcommand as ClapSubcommand};
+use clap::{CommandFactory, FromArgMatches, Parser, Subcommand as ClapSubcommand};
 
 /// A mytheclipse CLI application.
 #[derive(Parser, Debug)]
@@ -52,6 +52,17 @@ impl CliBuilder {
     }
 
     pub fn build(self) -> CliApp {
-        CliApp::parse()
+        // Apply the configured name/about to the derived clap Command so the
+        // builder's fields are honored in the rendered help/usage.
+        let Self { name, about } = self;
+        // clap's `Str`/`StyledStr` only accept 'static references, so leak
+        // the owned strings (build(self) consumes self once, so a single,
+        // process-lifetime leak is acceptable).
+        let name: &'static str = String::leak(name);
+        let about: &'static str = String::leak(about);
+        let cmd = <CliApp as CommandFactory>::command()
+            .name(name)
+            .about(about);
+        CliApp::from_arg_matches(&cmd.get_matches()).unwrap_or_else(|e| e.exit())
     }
 }