refactor(cli): Finalize OpenAI Codex Integration with OAuth

- Enhanced Codex model discovery by fetching available models from the API, with fallback to local cache and defaults.
- Updated the context compressor's summary target tokens to 2500 for improved performance.
- Added external credential detection for Codex CLI to streamline authentication.
- Refactored various components to ensure consistent handling of authentication and model selection across the application.

cli.py

@@ -841,12 +841,10 @@ class HermesCLI:
             or os.getenv("OPENROUTER_BASE_URL", CLI_CONFIG["model"]["base_url"])
         )
         self.api_key = api_key or os.getenv("OPENAI_API_KEY") or os.getenv("OPENROUTER_API_KEY")
-        # Max turns priority: CLI arg > env var > config file (agent.max_turns or root max_turns) > default
-        if max_turns != 60:  # CLI arg was explicitly set
         self._nous_key_expires_at: Optional[str] = None
         self._nous_key_source: Optional[str] = None
-        # Max turns priority: CLI arg > config file > env var > default
-        if max_turns is not None:
+        # Max turns priority: CLI arg > env var > config file (agent.max_turns or root max_turns) > default
+        if max_turns is not None:  # CLI arg was explicitly set
             self.max_turns = max_turns
         elif CLI_CONFIG["agent"].get("max_turns"):
             self.max_turns = CLI_CONFIG["agent"]["max_turns"]