feat(ask-AI):integrate voice interaction and multilingual support

[Yashaswini-Nanjundaiah]

What changed

Adds voice interaction capabilities to the Ask AI chatbot, including speech-to-text voice input, text-to-speech voice output, and multilingual response support. This PR integrates the completed work from the voice feature team into a single branch, preserving the existing Ask AI workflow while enabling voice-based interactions and multilingual functionality.

Related issue

Type of change

• Bug fix
• Feature
• Refactor (no behaviour change)
• Docs / comments only
• CI / tooling

Area affected

• Backend (Express / Mongoose)
• Frontend (React / Vite)
• Admin / Train tab (/admin/*)
• Community (/community — posts, comments, auto-answer)
• Search (hybrid text retrieval, training stats)
• Auth / middleware / samagama.in bridge
• Crons / schedulers / embedding-warm
• Observability (Sentry / logging / Discord alerts)
• Docs

CI verification

• cd apps/backend && npx tsc --noEmit exits 0
• cd apps/backend && npx vitest run — all tests pass
• cd apps/frontend && npx tsc --noEmit exits 0
• cd apps/frontend && npx vitest run — all tests pass
• pnpm run lint — 0 errors (152 warnings is the baseline)
• GitHub Actions green on the merge commit (CI, CodeQL, Build & Deploy)
• Tested with a real API hit or browser interaction if behaviour changed
• Tests added or updated for the change
• Single logical change — unrelated fixes noted in description, not fixed here
• Docs updated if route / API / env var / pipeline behaviour changed
• Rebased onto main, no merge commits

Notes for reviewer

This PR integrates the completed work from the voice feature team into a single branch.

Included features:

• Voice input (speech-to-text) integration.
• Voice output (text-to-speech) support.
• Multilingual translation layer integration.

The feature branches were reviewed and merged before this integration. Please review the overall functionality and compatibility of the integrated voice and multilingual features with the existing Ask AI workflow.