Fix negative blank line indentation

[ioquatix]

Summary

• Preserve raw AST indentation deltas instead of clamping them in build_indentation_deltas.
• Track semantic_level separately from visual current_level, so same-line nested opens only add one visual indentation level while later closes remain balanced.
• Add a regression for a top-level blank line after same-line nested array/hash opens.

Testing

• Direct ruby -Ilib regression for top-level blank line after same-line nested array/hash opens.
• Direct ruby -Ilib check for existing same-line array/hash indentation case.
• RUBYLIB=/Users/samuel/Developer/socketry/rubocop-socketry/lib bundle exec rubocop -d from async: no crash, reports one existing correctable offense in external/async-http/examples/race/client.rb:26.

Note: bundle exec sus test/rubocop/socketry/layout/consistent_blank_line_indentation.rb could not run because several locked gems are not installed locally.