Preserve caller options during hash and XML conversion

[OskarEichler]

Summary

HashMethods deletes caller include/exclude keys and XML#to_node writes its document into caller options. Use owned copies to make repeated calls stable and permit frozen options.

Reproduction

require 'representable/json/hash'
mod=Module.new { include Representable::JSON::Hash }
options={include: [:a]}.freeze
p({'a'=>1,'b'=>2}.extend(mod).to_hash(options))
# FrozenError before; {'a'=>1} after. Original options remain unchanged.

Verification

• Existing master suite on this isolated branch: 545 tests / 701 assertions, zero failures/errors, three existing skips on Ruby 3.2.11. Ruby 4.0.6 retains the same eight legacy inspection-format failures, zero errors and three skips. Existing tests/expectations are unchanged.
• 600 focused checks on Ruby 3.2.11/4.0.6 for this change. XML first-render uses a separate fresh-process check.
• Combined release-based verification with other focused fixes and attributed Use Setter in OverwriteOnNil if a :setter is defined #177/Hash value of null breaks parsing #264/Update MultiJSON usage to address deprecations #273 source backports: 544 tests / 700 assertions pass on Ruby 3.2.11, plus 4,410 focused checks and 36 boundary checks. Package retains 104 paths and unchanged compared metadata. All 36 runtime files compile on both Rubies; no newly introduced default Lint offenses.

Breaking changes / limitations

Caller options are no longer mutated. Code relying on consumed filters or an injected :doc key observes this correction. Nested values are not deep-copied.

No new/modified checked-in tests. Ruby 2.4–3.1, JRuby, Windows and Linux were not executed locally. Ruby >=2.4 and runtime dependency ranges remain unchanged. External test tooling supplies a legacy MiniTest alias and ruby-prof 1.7.x; no assertions were changed. No production verification is claimed.