chore: update dependencies and support modern Ruby

[Halvanhelv]

Summary

Every runtime dependency was unversioned and the development dependencies were pinned to Ruby 2.3-era releases. This upgrades everything to current versions, adds explicit constraints, and requires Ruby >= 3.2.

Dependencies

gem	before	after
connection_pool	unversioned	>= 2.4, < 4.0
deepl-rb	unversioned	~> 3.9
dry-initializer	unversioned	~> 3.2
ox	unversioned	~> 2.14
punkt-segmenter	unversioned	~> 0.9
ratelimit	unversioned	~> 1.1
redis	unversioned	>= 5.0, < 7.0
redis-namespace	unversioned	~> 1.11
rake	~> 10.0	~> 13.0
rspec	~> 3.0	~> 3.13
rubocop	unversioned	~> 1.90
simplecov	unversioned	~> 1.2
bundler	~> 1.14	removed
codeclimate-test-reporter	~> 1.0.0	removed (unmaintained)

Compatibility fixes

• Require cgi/escape, digest/md5, forwardable and stringio explicitly. They used to be pulled in transitively, which no longer holds.
• Pass the DeepL options as a positional hash. deepl-rb declares translate(text, source_lang, target_lang, options = {}), so the **options splat passed nothing when the hash was empty.
• Replace OpenStruct in the request spec with a Struct; OpenStruct is no longer available without an explicit require.
• Rename Chunker::Chunk members values/size to texts/bytesize so they stop shadowing Struct#values and Struct#size.
• Move the Tokenizer constants above the private section, where they are actually reachable.

CI and lint

• Replace Travis with GitHub Actions: the suite runs against Ruby 3.2, 3.3, 3.4 and 4.0, plus a RuboCop job.
• Update .rubocop.yml for RuboCop 1.90 — TargetRubyVersion, NewCops: enable, and Metrics/LineLength renamed to Layout/LineLength.

Version

Bumped to 1.1.0.

Test plan

• bundle exec rspec — 28 examples, 0 failures, on both Ruby 4.0.5 and 3.2.4.
• bundle exec rubocop — 0 offenses.

Note

The deleted .travis.yml carried a CodeClimate repo_token in plain text. It remains in the git history, so that token should be rotated on the CodeClimate side.

https://claude.ai/code/session_01Pda49PcgziFVnibkKKjXRE