Add limiter telemetry counters

[samuel-williams-shopify]

Summary

• add standardized telemetry counters for limited and queued limiters
• expose acquired, available, waiting, and reacquire-waiting counts in statistics
• add JSON serialization via the existing statistics surface

Tests

• PATH="/Users/samuel/.rubies/ruby-3.4.4/bin:/opt/local/bin:/opt/local/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/opt/pmk/env/global/bin:/Library/Apple/usr/bin:/Users/samuel/.codex/tmp/arg0/codex-arg0SfNZtY:/nix/store/c87rrnqsdlg7h7mbdqa2qww292cjkqr4-codex-0.130.0/lib/codex/node_modules/.pnpm/@openai+codex@0.130.0-darwin-arm64/node_modules/@openai/codex/vendor/aarch64-apple-darwin/path:/nix/store/c87rrnqsdlg7h7mbdqa2qww292cjkqr4-codex-0.130.0/bin:/Users/samuel/.local/state/tec/profiles/base/current/global/share/dev/bin/user:/Users/samuel/.local/state/tec/profiles/base/current/global/bin:/Users/samuel/.dev/userprofile/bin:/opt/dev/bin/user:/nix/var/nix/profiles/default/bin:/opt/homebrew/bin:/opt/homebrew/sbin" bundle exec sus
• PATH="/Users/samuel/.rubies/ruby-3.4.4/bin:/opt/local/bin:/opt/local/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/opt/pmk/env/global/bin:/Library/Apple/usr/bin:/Users/samuel/.codex/tmp/arg0/codex-arg0SfNZtY:/nix/store/c87rrnqsdlg7h7mbdqa2qww292cjkqr4-codex-0.130.0/lib/codex/node_modules/.pnpm/@openai+codex@0.130.0-darwin-arm64/node_modules/@openai/codex/vendor/aarch64-apple-darwin/path:/nix/store/c87rrnqsdlg7h7mbdqa2qww292cjkqr4-codex-0.130.0/bin:/Users/samuel/.local/state/tec/profiles/base/current/global/share/dev/bin/user:/Users/samuel/.local/state/tec/profiles/base/current/global/bin:/Users/samuel/.dev/userprofile/bin:/opt/dev/bin/user:/nix/var/nix/profiles/default/bin:/opt/homebrew/bin:/opt/homebrew/sbin" bundle exec rubocop