Add brainfuck editor and interpreter tool

[rodrigogiraoserrao]

Summary

• add a CodeMirror-based UI card for writing and running brainfuck programs with configurable input modes
• implement a browser brainfuck interpreter that wraps cell values, extends the tape, and handles EOF input as zero while showing ASCII and byte outputs
• document the new brainfuck interpreter tool

Testing

• not run (not requested)

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Codex Task