fix: update MiniMax/Z.AI model lists, pass base_url to AIAgent

- Update _PROVIDER_MODELS['minimax'] from stale ABAB 6.5 models to
  current MiniMax-M2.7/M2.5/M2.1 lineup (matching hermes-agent upstream)
- Update _PROVIDER_MODELS['zai'] from GLM-4 to current GLM-5/4.7/4.5
  lineup (matching hermes-agent upstream)
- Extend resolve_model_provider() to also return base_url from config.yaml,
  so providers with custom endpoints (MiniMax, Z.AI) are routed correctly
- Pass base_url to AIAgent in both streaming and sync chat paths

Fixes #6

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/streaming.py

@@ -100,10 +100,11 @@ def _run_agent_streaming(session_id, msg_text, model, workspace, stream_id, atta
 
             if AIAgent is None:
                 raise ImportError("AIAgent not available -- check that hermes-agent is on sys.path")
-            resolved_model, resolved_provider = resolve_model_provider(model)
+            resolved_model, resolved_provider, resolved_base_url = resolve_model_provider(model)
             agent = AIAgent(
                 model=resolved_model,
                 provider=resolved_provider,
+                base_url=resolved_base_url,
                 platform='cli',
                 quiet_mode=True,
                 enabled_toolsets=CLI_TOOLSETS,