Phase 5: AI provider system with local and cloud support

- Implement AIProvider base interface with chat() and is_available()
- Add LocalProvider connecting to bundled llama-server via OpenAI SDK
- Add OpenAIProvider for direct OpenAI API access
- Add AnthropicProvider for Anthropic Claude API
- Add LiteLLMProvider for multi-provider gateway
- Build AIProviderService with provider routing, auto-selection,
  and transcript context injection
- Add ai.chat IPC handler supporting chat, list_providers, set_provider,
  and configure actions
- Add ai_chat, ai_list_providers, ai_configure Tauri commands
- Build interactive AIChatPanel with message history, quick actions
  (Summarize, Action Items), and transcript context awareness
- Tests: 30 Python, 6 Rust, 0 Svelte errors

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

python/voice_to_notes/ipc/handlers.py

@@ -135,6 +135,83 @@ def make_export_handler() -> HandlerFunc:
     return handler
 
 
+def make_ai_chat_handler() -> HandlerFunc:
+    """Create an AI chat handler with persistent AIProviderService."""
+    from voice_to_notes.services.ai_provider import create_default_service
+
+    service = create_default_service()
+
+    def handler(msg: IPCMessage) -> IPCMessage:
+        payload = msg.payload
+        action = payload.get("action", "chat")
+
+        if action == "list_providers":
+            return IPCMessage(
+                id=msg.id,
+                type="ai.providers",
+                payload={"providers": service.list_providers()},
+            )
+
+        if action == "set_provider":
+            service.set_active(payload["provider"])
+            return IPCMessage(
+                id=msg.id,
+                type="ai.provider_set",
+                payload={"provider": payload["provider"]},
+            )
+
+        if action == "configure":
+            # Re-create a provider with custom settings
+            provider_name = payload.get("provider", "")
+            config = payload.get("config", {})
+            if provider_name == "local":
+                from voice_to_notes.providers.local_provider import LocalProvider
+
+                service.register_provider("local", LocalProvider(
+                    base_url=config.get("base_url", "http://localhost:8080"),
+                    model=config.get("model", "local"),
+                ))
+            elif provider_name == "openai":
+                from voice_to_notes.providers.openai_provider import OpenAIProvider
+
+                service.register_provider("openai", OpenAIProvider(
+                    api_key=config.get("api_key"),
+                    model=config.get("model", "gpt-4o-mini"),
+                ))
+            elif provider_name == "anthropic":
+                from voice_to_notes.providers.anthropic_provider import AnthropicProvider
+
+                service.register_provider("anthropic", AnthropicProvider(
+                    api_key=config.get("api_key"),
+                    model=config.get("model", "claude-sonnet-4-6"),
+                ))
+            elif provider_name == "litellm":
+                from voice_to_notes.providers.litellm_provider import LiteLLMProvider
+
+                service.register_provider("litellm", LiteLLMProvider(
+                    model=config.get("model", "gpt-4o-mini"),
+                ))
+            return IPCMessage(
+                id=msg.id,
+                type="ai.configured",
+                payload={"provider": provider_name},
+            )
+
+        # Default: chat
+        response = service.chat(
+            messages=payload.get("messages", []),
+            transcript_context=payload.get("transcript_context", ""),
+            **{k: v for k, v in payload.items() if k not in ("action", "messages", "transcript_context")},
+        )
+        return IPCMessage(
+            id=msg.id,
+            type="ai.response",
+            payload={"response": response},
+        )
+
+    return handler
+
+
 def hardware_detect_handler(msg: IPCMessage) -> IPCMessage:
     """Detect hardware capabilities and return recommendations."""
     from voice_to_notes.hardware.detect import detect_hardware