Refactor subagent and workflow domain models; migrate access tiers and events to domain module

- Moved `AccessTier` and `SubagentEvent` enums to `zesdex_domain::subagent`.
- Consolidated workflow-related types into `zesdex_domain::workflow`.
- Updated references across the codebase to use the new domain models.
- Refactored tool execution logic to utilize a new `ToolExecutor` trait.
- Enhanced `AgentTurnService` to handle tool calls and events more effectively.
- Adjusted API handlers and state management to align with new domain structure.

apps/infrastructure/src/subagent/provider.rs

@@ -35,12 +35,14 @@ impl SubagentProvider {
     ///
     /// Use this for a plain text-in/text-out conversation.
     #[tracing::instrument(skip(self, messages))]
-    pub fn chat(
+    pub async fn chat(
         &self,
         messages: &[ChatMessage],
     ) -> Result<(ChatMessage, Option<(u64, u64)>)> {
+        use zesdex_application::ports::ProviderService;
         self.client
-            .chat_with_tools_non_streaming(messages, None, Some(4096), None, None)
+            .chat(messages, None, Some(4096), None)
+            .await
     }
 
     /// Send messages with available tool definitions.
@@ -48,14 +50,16 @@ impl SubagentProvider {
     /// Automatically converts the `&[Box<dyn Tool>]` slice to
     /// `Vec<ToolDef>` before passing to the underlying client.
     #[tracing::instrument(skip(self, messages, tools))]
-    pub fn chat_with_tools(
+    pub async fn chat_with_tools(
         &self,
         messages: &[ChatMessage],
         tools: &[Box<dyn Tool>],
     ) -> Result<(ChatMessage, Option<(u64, u64)>)> {
         let defs = tool_defs(tools);
+        use zesdex_application::ports::ProviderService;
         self.client
-            .chat_with_tools_non_streaming(messages, Some(defs), Some(4096), None, None)
+            .chat(messages, Some(defs), Some(4096), None)
+            .await
     }
 }