hermes - 💡(How to fix) Fix Dead config key: smart_model_routing has no implementation

Description

The config key smart_model_routing appears in the default config.yaml template and is referenced in AGENTS.md, but has zero implementation in Python source code.

Evidence

• config.yaml contains a full smart_model_routing section with enabled, max_simple_chars, max_simple_words, cheap_model, etc. — all default values
• AGENTS.md mentions Smart Model Routing under "5. Smart Model Routing（半自动）" as a feature
• grep -r "smart_model" --include="*.py" . returns zero results — no Python code ever reads or acts on these config values
• This is a dead config entry that creates confusion (users see it in their config and docs but it does nothing)

Expected

Either:

1. Implement the feature (if planned), or
2. Remove the config key from the default template and clean up the docs reference

Impact

Users who discover this config key (e.g. by browsing their config.yaml or reading AGENTS.md) may try to use it and find it silently does nothing.