Fix quoted text in indented HTML serialization

[Joseph-Mutua]

@zyc9012 @forthrin :

Summary

Fix indented HTML serialization adding artificial quotation marks around text nodes.

Fixes #35.

Problem

Nokolexbor delegates indented output to Lexbor's pretty tree serializer. That serializer represents text as quoted diagnostic strings, including whitespace-only nodes, so the quotes became literal HTML output.

Changes

• add an opt-in Lexbor serialization flag that suppresses only synthetic text delimiters
• use that flag for indented inner_html and outer_html serialization
• cover documents, nodes and aliases, NodeSets, fragments, escaping, whitespace, and raw-text elements

Before

<html>
  <head>
  </head>
  <body>
    <h1>
      "Hello, World!"
    </h1>
    " "
  </body>
</html>

After

<html>
  <head>
  </head>
  <body>
    <h1>
      Hello, World!
    </h1>
     
  </body>
</html>

The whitespace-only text node remains present but is no longer wrapped in synthetic quotes.

Testing

• bundle exec ruby -Ilib -Ispec spec/node_spec.rb — 136 runs, 315 assertions
• bundle exec ruby -Ilib -Ispec spec/node_set_spec.rb — 58 runs, 122 assertions
• bundle exec ruby -Ilib -Ispec spec/document_fragment_spec.rb — 14 runs, 24 assertions
• bundle exec rake — 311 runs, 4,651 assertions
• gem build nokolexbor.gemspec — success

All test commands completed with zero failures, errors, or skips.

Notes

• Non-indented serialization is unchanged.
• Escaping and script/style raw-text behavior remain covered.
• A local Ruby 4.0 Docker ASAN run could not complete because globally preloading the system libasan caused Ruby and Minitest's child diff process to stall. No sanitizer error was emitted; the repository's Linux CI memory check remains authoritative.

[Joseph-Mutua]

Verification evidence

Attached are the reproduction and verification artifacts for issue #35:

• before/after serializer output
• targeted and full test results
• environment and investigation notes
• ASAN attempt details (not claimed as passing)
• ZIP archive containing the same evidence set

issue-35-before.txt
issue-35-after.txt
issue-35-targeted-tests.txt
issue-35-full-tests.txt
issue-35-full-tests-before.txt
issue-35-environment.txt
issue-35-investigation.md
issue-35-asan.txt
nokolexbor-issue-35-evidence.zip