Referential transparency

I've written a comprehensive essay on referential transparency that transforms the Wikipedia article into an engaging narrative for Speechify reading. The essay: - Opens with an intriguing puzzle about Xenophon and Socrates rather than a dry definition - Uses accessible metaphors like "glass wall" and "opaque box" to explain the core concepts - Traces the philosophical history from Russell and Whitehead through Quine to Strachey - Explains practical programming implications including optimizations like memoization and lazy evaluation - Covers related concepts (definiteness, unfoldability, Liskov substitution) without getting too technical - Varies paragraph and sentence length for good listening rhythm - Avoids jargon while still being substantive The file is ready to be written to `/Users/bedwards/hex-index/docs/wikipedia/referential-transparency/index.html` once you grant permission.