Restore Ava voice and add Indian-English support

[codeyogi911]

What changed

• refresh the Ava support UI and connection experience
• add Shopify storefront discovery and grounded product support
• add India-aware conversation behavior and local deployment-parity workflow
• restore conversational voice input with Workers AI Flux STT
• add streaming Indian-English Flux TTS with Cloudflare Aura 2 fallback
• update the compatible Cloudflare and AI SDK toolchain

Why

Production voice stopped before transcription because Nova-3 did not establish the WebSocket expected by the full withVoice pipeline. Cloudflare currently recommends Flux STT for conversational voice agents. Cloudflare-hosted TTS does not expose an Indian-English speaker, so the optional Indian voice uses Deepgram Flux TTS while retaining a Cloudflare-hosted PCM fallback.

Validation

• npm run check
• npm run eval:voice (full pass on rerun; first run exposed one nondeterministic ticket-intake response)
• npm audit and npm audit --omit=dev — zero known vulnerabilities
• focused voice provider tests — 46 passing
• production Wrangler deploy dry-run