fix: update examples to use stream() and haiku model

- Change session.receive() to session.stream() (API change)
- Use 'haiku' model instead of 'sonnet' (more reliable)
- Clean up debug output

🤖 Generated with [Letta Code](https://letta.com)

Co-Authored-By: Letta <noreply@letta.com>

examples/bug-fixer/types.ts

@@ -12,5 +12,5 @@ export interface BugFixerConfig {
 }
 
 export const DEFAULT_CONFIG: BugFixerConfig = {
-  model: 'sonnet',
+  model: 'haiku',
 };