fix: switch to OpenAI client for llm-proxy compatibility

- Replace Anthropic SDK with OpenAI SDK (proxy uses OpenAI-compatible API)
- Add combined post fetching to include hidden/moderated posts
- Update system prompt to be more thorough at catching violations
- Add --debug flag to CLI for troubleshooting

pyproject.toml

@@ -8,7 +8,7 @@ dependencies = [
     "httpx>=0.27",
     "click>=8.1",
     "rich>=13.0",
-    "anthropic>=0.30",
+    "openai>=1.0",
     "python-dateutil>=2.9",
     "python-dotenv>=1.0",
 ]