fix: first-run guard stuck in loop when provider configured via config.yaml (#4298)

The _has_any_provider_configured() guard only checked env vars, .env file,
and auth.json — missing config.yaml model.provider/base_url/api_key entirely.
Users who configured a provider through setup (saving to config.yaml) but had
empty API key placeholders in .env from the install template were permanently
blocked by the 'not configured' message.

Changes:
- _has_any_provider_configured() now checks config.yaml model section for
  explicit provider, base_url, or api_key — covers custom endpoints and
  providers that store credentials in config rather than env vars
- .env.example: comment out all empty API key placeholders so they don't
  pollute the environment when copied to .env by the installer
- .env.example: mark LLM_MODEL as deprecated (config.yaml is source of truth)
- 4 new tests for the config.yaml detection path

Reported by OkadoOP on Discord.

tests/test_api_key_providers.py

@@ -645,6 +645,83 @@ class TestHasAnyProviderConfigured:
         from hermes_cli.main import _has_any_provider_configured
         assert _has_any_provider_configured() is False
 
+    def test_config_provider_counts(self, monkeypatch, tmp_path):
+        """config.yaml with model.provider set should count as configured."""
+        import yaml
+        from hermes_cli import config as config_module
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        config_file = hermes_home / "config.yaml"
+        config_file.write_text(yaml.dump({
+            "model": {"default": "anthropic/claude-opus-4.6", "provider": "openrouter"},
+        }))
+        monkeypatch.setattr(config_module, "get_env_path", lambda: hermes_home / ".env")
+        monkeypatch.setattr(config_module, "get_hermes_home", lambda: hermes_home)
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+        # Clear all provider env vars
+        for var in ("OPENROUTER_API_KEY", "OPENAI_API_KEY", "ANTHROPIC_API_KEY",
+                     "ANTHROPIC_TOKEN", "OPENAI_BASE_URL"):
+            monkeypatch.delenv(var, raising=False)
+        from hermes_cli.main import _has_any_provider_configured
+        assert _has_any_provider_configured() is True
+
+    def test_config_base_url_counts(self, monkeypatch, tmp_path):
+        """config.yaml with model.base_url set (custom endpoint) should count."""
+        import yaml
+        from hermes_cli import config as config_module
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        config_file = hermes_home / "config.yaml"
+        config_file.write_text(yaml.dump({
+            "model": {"default": "my-model", "base_url": "http://localhost:11434/v1"},
+        }))
+        monkeypatch.setattr(config_module, "get_env_path", lambda: hermes_home / ".env")
+        monkeypatch.setattr(config_module, "get_hermes_home", lambda: hermes_home)
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+        for var in ("OPENROUTER_API_KEY", "OPENAI_API_KEY", "ANTHROPIC_API_KEY",
+                     "ANTHROPIC_TOKEN", "OPENAI_BASE_URL"):
+            monkeypatch.delenv(var, raising=False)
+        from hermes_cli.main import _has_any_provider_configured
+        assert _has_any_provider_configured() is True
+
+    def test_config_api_key_counts(self, monkeypatch, tmp_path):
+        """config.yaml with model.api_key set should count."""
+        import yaml
+        from hermes_cli import config as config_module
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        config_file = hermes_home / "config.yaml"
+        config_file.write_text(yaml.dump({
+            "model": {"default": "my-model", "api_key": "sk-test-key"},
+        }))
+        monkeypatch.setattr(config_module, "get_env_path", lambda: hermes_home / ".env")
+        monkeypatch.setattr(config_module, "get_hermes_home", lambda: hermes_home)
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+        for var in ("OPENROUTER_API_KEY", "OPENAI_API_KEY", "ANTHROPIC_API_KEY",
+                     "ANTHROPIC_TOKEN", "OPENAI_BASE_URL"):
+            monkeypatch.delenv(var, raising=False)
+        from hermes_cli.main import _has_any_provider_configured
+        assert _has_any_provider_configured() is True
+
+    def test_config_dict_no_provider_no_creds_still_false(self, monkeypatch, tmp_path):
+        """config.yaml model dict with only 'default' key and no creds stays false."""
+        import yaml
+        from hermes_cli import config as config_module
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        config_file = hermes_home / "config.yaml"
+        config_file.write_text(yaml.dump({
+            "model": {"default": "anthropic/claude-opus-4.6"},
+        }))
+        monkeypatch.setattr(config_module, "get_env_path", lambda: hermes_home / ".env")
+        monkeypatch.setattr(config_module, "get_hermes_home", lambda: hermes_home)
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+        for var in ("OPENROUTER_API_KEY", "OPENAI_API_KEY", "ANTHROPIC_API_KEY",
+                     "ANTHROPIC_TOKEN", "OPENAI_BASE_URL"):
+            monkeypatch.delenv(var, raising=False)
+        from hermes_cli.main import _has_any_provider_configured
+        assert _has_any_provider_configured() is False
+
     def test_claude_code_creds_counted_when_hermes_configured(self, monkeypatch, tmp_path):
         """Claude Code credentials should count when Hermes has been explicitly configured."""
         import yaml