feat: migrate to @elevenlabs/react v1 with granular hooks (#68)

* feat: migrate to @elevenlabs/client and @elevenlabs/react v1.0.0-rc.1

- Update @elevenlabs/client and @elevenlabs/react to 1.0.0-rc.1
- Wrap useConversation consumers with ConversationProvider (required in v1)
- Guard getInputVolume/getOutputVolume with try-catch for pre-session calls
- Add NEXT_PUBLIC_ELEVENLABS_AGENT_ID to .env.example

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* refactor: use granular conversation hooks and remove built-in provider from ConversationBar

Replace local connection state (agentState, isMuted) with granular hooks
(useConversationStatus, useConversationControls, useConversationInput)
across all conversation components. Remove ConversationProvider from
ConversationBar so it uses whatever provider exists in the tree.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: correct indentation in CardsDemo

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Ran format:write

* refactor: remove ConversationProvider from page components

Conversation components now expect a provider from the caller.
The CardsDemo page provides the single shared provider.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: upgrade @elevenlabs/client and @elevenlabs/react from RC to stable

Upgrade @elevenlabs/client (1.0.0-rc.1 → ^1.7.0) and
@elevenlabs/react (1.0.0-rc.1 → ^1.6.0) to their latest
stable releases. No code changes needed — the codebase already
uses the new API patterns.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: wrap registry views with conversation provider

Co-authored-by: Kræn Hansen <mail@kraenhansen.dk>

* fix: provide conversation context for block previews

Co-authored-by: Kræn Hansen <mail@kraenhansen.dk>

* fix: wrap registry component previews with provider

Co-authored-by: Kræn Hansen <mail@kraenhansen.dk>

* Ran prettier

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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Cursor Agent <cursoragent@cursor.com>