chore: remove nous-api provider (API key path)

Nous Portal only supports OAuth authentication. Remove the 'nous-api'
provider which allowed direct API key access via NOUS_API_KEY env var.

Removed from:
- hermes_cli/auth.py: PROVIDER_REGISTRY entry + aliases
- hermes_cli/config.py: OPTIONAL_ENV_VARS entry
- hermes_cli/setup.py: setup wizard option + model selection handler
  (reindexed remaining provider choices)
- agent/auxiliary_client.py: docstring references
- tests/test_runtime_provider_resolution.py: nous-api test
- tests/integration/test_web_tools.py: renamed dict key

hermes_cli/config.py

@@ -242,14 +242,6 @@ REQUIRED_ENV_VARS = {}
 # Optional environment variables that enhance functionality
 OPTIONAL_ENV_VARS = {
     # ── Provider (handled in provider selection, not shown in checklists) ──
-    "NOUS_API_KEY": {
-        "description": "Nous Portal API key (direct API key access to Nous inference)",
-        "prompt": "Nous Portal API key",
-        "url": "https://portal.nousresearch.com",
-        "password": True,
-        "category": "provider",
-        "advanced": True,
-    },
     "NOUS_BASE_URL": {
         "description": "Nous Portal base URL override",
         "prompt": "Nous Portal base URL (leave empty for default)",