[szhaomsft]

Summary

• Move Azure Realtime Fast from native speech-to-speech to Realtime text response + Azure HD, retaining the explicitly labeled Lite-tier reference.
• Bill native audio input, text response, and Lite standard-speech output; do not add native audio output, separate STT, or GPT Live session charges.
• Correct model selection, comparison rows, CSV pipeline/HD-meter provenance, price notes, and documentation. Azure Realtime remains on the Pro native speech-to-speech pipeline; BYOM remains unavailable for both Azure models.

This corrects the Fast pipeline introduced in #68. The branch includes latest main; the diff is limited to four cost-calculator files.

Validation

• node --test tools\cost_calculator\calculator.test.mjs — all 26 tests pass, covering exact Lite hybrid totals, caching, reasoning, silence, and model/pipeline eligibility.
• node --check tools\cost_calculator\app.mjs
• git diff origin/main...HEAD --check
• Browser verification confirmed Fast appears only under the hybrid selector and comparison, includes Azure HD output without native output charges, exports five hybrid prompt scenarios with the Lite HD meter, and preserves Azure Realtime native pricing.

With default assumptions, Fast is $0.020687 per 90-second call ($0.013791 per minute). No price snapshot changes are included.