feat: add ability to run multiple agents via tabbed views (#47)

### Explanation

_No response_

### Issue

Closes #30 Closes #41

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### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

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### Tests

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Reviewed-on: #47
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/lib/types/messages.ts

@@ -1,3 +1,11 @@
+export interface TerminalLine {
+  id: string;
+  type: "user" | "assistant" | "system" | "tool" | "error";
+  content: string;
+  timestamp: Date;
+  toolName?: string;
+}
+
 export interface SystemInitMessage {
   type: "system";
   subtype: "init";
@@ -115,6 +123,7 @@ export interface PermissionPromptEvent {
   tool_name: string;
   tool_input: Record<string, unknown>;
   description: string;
+  conversation_id?: string;
 }
 
 export type ConnectionStatus = "disconnected" | "connecting" | "connected" | "error";