fix(model-picker): use config key instead of display-name slug for named custom providers (#75087)

[RelaxJonh]

Summary

Fixes #75087.

select_provider_and_model() generated the picker key for named custom providers as custom:<name-lowercased-and-spaces-replaced>, derived from the display name. The actual config key under providers: was only used when resolve_provider() raised AuthError — exactly backwards.

When a user selects a provider via the interactive hermes model picker, the slug is saved to model.provider. resolve_provider_full() then does a direct providers_dict.get() with that slug, which returns None because the real key is different. The agent still works at runtime via the credential-pool fallback, but any code path using resolve_provider_full() (most prominently the Desktop model-switch menu) triggers "Unknown provider" warnings and falls back to default settings.

Fix

Always use provider_key when available; fall back to the display-name slug only when no config key exists.

-            key = "custom:" + name.lower().replace(" ", "-")
             provider_key = (entry.get("provider_key") or "").strip()
             if provider_key:
-                try:
-                    resolve_provider(provider_key)
-                except AuthError:
-                    key = provider_key
+                key = provider_key
+            else:
+                key = "custom:" + name.lower().replace(" ", "-")

Testing

• Configured a named custom provider with a config key different from its display name (e.g. providers: { litellm: { name: "LiteLLM Proxy", ... } })
• Ran hermes model and selected the provider
• Verified model.provider is saved as litellm (not custom:litellm-proxy)
• Verified no "Unknown provider" warnings in subsequent resolution

[teknium1]

Thanks for tracing the display-name/config-key mismatch. The premise is real, but this patch changes only the picker map and does not complete the persistence contract.

Problems

• hermes_cli/main.py:3154 changes the temporary selected key, but _model_flow_named_custom() still writes model.provider as custom:<provider_key> in hermes_cli/model_setup_flows.py:1638-1641.
• That value still misses the keyed providers: entry: resolve_user_provider() uses user_config.get(name) at hermes_cli/providers.py:685, so custom:litellm does not resolve providers.litellm.

Suggested changes

• Update the persistence/resolution path so the selected identity is resolvable end-to-end, and add a picker-level regression test for a config key that differs from its display name.

Automated hermes-sweeper review.

[teknium1]

This only changes the picker-map key. _model_flow_named_custom() still persists model.provider as custom:<provider_key> (hermes_cli/model_setup_flows.py:1638-1641), while resolve_user_provider() looks up the raw value with user_config.get(name) (hermes_cli/providers.py:685). Please update that persistence/resolution path and add an end-to-end keyed-provider regression test.