refactor: remove smart_model_routing feature (#12732)

Smart model routing (auto-routing short/simple turns to a cheap model
across providers) was opt-in and disabled by default.  This removes the
feature wholesale: the routing module, its config keys, docs, tests, and
the orchestration scaffolding it required in cli.py / gateway/run.py /
cron/scheduler.py.

The /fast (Priority Processing / Anthropic fast mode) feature kept its
hooks into _resolve_turn_agent_config — those still build a route dict
and attach request_overrides when the model supports it; the route now
just always uses the session's primary model/provider rather than
running prompts through choose_cheap_model_route() first.

Also removed:
- DEFAULT_CONFIG['smart_model_routing'] block and matching commented-out
  example sections in hermes_cli/config.py and cli-config.yaml.example
- _load_smart_model_routing() / self._smart_model_routing on GatewayRunner
- self._smart_model_routing / self._active_agent_route_signature on
  HermesCLI (signature kept; just no longer initialised through the
  smart-routing pipeline)
- route_label parameter on HermesCLI._init_agent (only set by smart
  routing; never read elsewhere)
- 'Smart Model Routing' section in website/docs/integrations/providers.md
- tip in hermes_cli/tips.py
- entries in hermes_cli/dump.py + hermes_cli/web_server.py
- row in skills/autonomous-ai-agents/hermes-agent/SKILL.md

Tests:
- Deleted tests/agent/test_smart_model_routing.py
- Rewrote tests/agent/test_credential_pool_routing.py to target the
  simplified _resolve_turn_agent_config directly (preserves credential
  pool propagation + 429 rotation coverage)
- Dropped 'cheap model' test from test_cli_provider_resolution.py
- Dropped resolve_turn_route patches from cli + gateway test_fast_command
  — they now exercise the real method end-to-end
- Removed _smart_model_routing stub assignments from gateway/cron test
  helpers

Targeted suites: 74/74 in the directly affected test files;
tests/agent + tests/cron + tests/cli pass except 5 failures that
already exist on main (cron silent-delivery + alias quick-command).

cron/scheduler.py

@@ -826,7 +826,6 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
 
         # Provider routing
         pr = _cfg.get("provider_routing", {})
-        smart_routing = _cfg.get("smart_model_routing", {}) or {}
 
         from hermes_cli.runtime_provider import (
             resolve_runtime_provider,
@@ -843,24 +842,9 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
             message = format_runtime_provider_error(exc)
             raise RuntimeError(message) from exc
 
-        from agent.smart_model_routing import resolve_turn_route
-        turn_route = resolve_turn_route(
-            prompt,
-            smart_routing,
-            {
-                "model": model,
-                "api_key": runtime.get("api_key"),
-                "base_url": runtime.get("base_url"),
-                "provider": runtime.get("provider"),
-                "api_mode": runtime.get("api_mode"),
-                "command": runtime.get("command"),
-                "args": list(runtime.get("args") or []),
-            },
-        )
-
         fallback_model = _cfg.get("fallback_providers") or _cfg.get("fallback_model") or None
         credential_pool = None
-        runtime_provider = str(turn_route["runtime"].get("provider") or "").strip().lower()
+        runtime_provider = str(runtime.get("provider") or "").strip().lower()
         if runtime_provider:
             try:
                 from agent.credential_pool import load_pool
@@ -877,13 +861,13 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
                 logger.debug("Job '%s': failed to load credential pool for %s: %s", job_id, runtime_provider, e)
 
         agent = AIAgent(
-            model=turn_route["model"],
-            api_key=turn_route["runtime"].get("api_key"),
-            base_url=turn_route["runtime"].get("base_url"),
-            provider=turn_route["runtime"].get("provider"),
-            api_mode=turn_route["runtime"].get("api_mode"),
-            acp_command=turn_route["runtime"].get("command"),
-            acp_args=turn_route["runtime"].get("args"),
+            model=model,
+            api_key=runtime.get("api_key"),
+            base_url=runtime.get("base_url"),
+            provider=runtime.get("provider"),
+            api_mode=runtime.get("api_mode"),
+            acp_command=runtime.get("command"),
+            acp_args=runtime.get("args"),
             max_iterations=max_iterations,
             reasoning_config=reasoning_config,
             prefill_messages=prefill_messages,