feat(ai): add support for Ollama AI provider configuration

* Update README with Ollama integration details
* Add Ollama configuration to example YAML files
* Implement Ollama provider in AI factory
* Add tests for Ollama provider functionality
* Enhance config validation for Ollama settings

internal/config/config.go

@@ -62,6 +62,7 @@ type AIConfig struct {
 	Embeddings AIEmbeddingConfig  `yaml:"embeddings"`
 	Metadata   AIMetadataConfig   `yaml:"metadata"`
 	LiteLLM    LiteLLMConfig      `yaml:"litellm"`
+	Ollama     OllamaConfig       `yaml:"ollama"`
 	OpenRouter OpenRouterAIConfig `yaml:"openrouter"`
 }
 
@@ -84,6 +85,12 @@ type LiteLLMConfig struct {
 	MetadataModel   string            `yaml:"metadata_model"`
 }
 
+type OllamaConfig struct {
+	BaseURL        string            `yaml:"base_url"`
+	APIKey         string            `yaml:"api_key"`
+	RequestHeaders map[string]string `yaml:"request_headers"`
+}
+
 type OpenRouterAIConfig struct {
 	BaseURL      string            `yaml:"base_url"`
 	APIKey       string            `yaml:"api_key"`

internal/config/loader.go

@@ -73,6 +73,10 @@ func defaultConfig() Config {
 				Model:       "gpt-4o-mini",
 				Temperature: 0.1,
 			},
+			Ollama: OllamaConfig{
+				BaseURL: "http://localhost:11434/v1",
+				APIKey:  "ollama",
+			},
 		},
 		Capture: CaptureConfig{
 			Source: DefaultSource,
@@ -97,6 +101,8 @@ func applyEnvOverrides(cfg *Config) {
 	overrideString(&cfg.Database.URL, "OB1_DATABASE_URL")
 	overrideString(&cfg.AI.LiteLLM.BaseURL, "OB1_LITELLM_BASE_URL")
 	overrideString(&cfg.AI.LiteLLM.APIKey, "OB1_LITELLM_API_KEY")
+	overrideString(&cfg.AI.Ollama.BaseURL, "OB1_OLLAMA_BASE_URL")
+	overrideString(&cfg.AI.Ollama.APIKey, "OB1_OLLAMA_API_KEY")
 	overrideString(&cfg.AI.OpenRouter.APIKey, "OB1_OPENROUTER_API_KEY")
 
 	if value, ok := os.LookupEnv("OB1_SERVER_PORT"); ok {

internal/config/loader_test.go

@@ -69,3 +69,51 @@ logging:
 		t.Fatalf("server port = %d, want 9090", cfg.Server.Port)
 	}
 }
+
+func TestLoadAppliesOllamaEnvOverrides(t *testing.T) {
+	configPath := filepath.Join(t.TempDir(), "test.yaml")
+	if err := os.WriteFile(configPath, []byte(`
+server:
+  port: 8080
+mcp:
+  path: "/mcp"
+auth:
+  keys:
+    - id: "test"
+      value: "secret"
+database:
+  url: "postgres://from-file"
+ai:
+  provider: "ollama"
+  embeddings:
+    model: "nomic-embed-text"
+    dimensions: 768
+  metadata:
+    model: "llama3.2"
+  ollama:
+    base_url: "http://localhost:11434/v1"
+    api_key: "ollama"
+search:
+  default_limit: 10
+  max_limit: 50
+logging:
+  level: "info"
+`), 0o600); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	t.Setenv("OB1_OLLAMA_BASE_URL", "https://ollama.example.com/v1")
+	t.Setenv("OB1_OLLAMA_API_KEY", "remote-key")
+
+	cfg, _, err := Load(configPath)
+	if err != nil {
+		t.Fatalf("Load() error = %v", err)
+	}
+
+	if cfg.AI.Ollama.BaseURL != "https://ollama.example.com/v1" {
+		t.Fatalf("ollama base url = %q, want env override", cfg.AI.Ollama.BaseURL)
+	}
+	if cfg.AI.Ollama.APIKey != "remote-key" {
+		t.Fatalf("ollama api key = %q, want env override", cfg.AI.Ollama.APIKey)
+	}
+}

internal/config/validate.go

@@ -28,7 +28,7 @@ func (c Config) Validate() error {
 	}
 
 	switch c.AI.Provider {
-	case "litellm", "openrouter":
+	case "litellm", "ollama", "openrouter":
 	default:
 		return fmt.Errorf("invalid config: unsupported ai.provider %q", c.AI.Provider)
 	}
@@ -45,6 +45,13 @@ func (c Config) Validate() error {
 		if strings.TrimSpace(c.AI.LiteLLM.APIKey) == "" {
 			return fmt.Errorf("invalid config: ai.litellm.api_key is required when ai.provider=litellm")
 		}
+	case "ollama":
+		if strings.TrimSpace(c.AI.Ollama.BaseURL) == "" {
+			return fmt.Errorf("invalid config: ai.ollama.base_url is required when ai.provider=ollama")
+		}
+		if strings.TrimSpace(c.AI.Ollama.APIKey) == "" {
+			return fmt.Errorf("invalid config: ai.ollama.api_key is required when ai.provider=ollama")
+		}
 	case "openrouter":
 		if strings.TrimSpace(c.AI.OpenRouter.BaseURL) == "" {
 			return fmt.Errorf("invalid config: ai.openrouter.base_url is required when ai.provider=openrouter")

internal/config/validate_test.go

@@ -19,6 +19,10 @@ func validConfig() Config {
 				BaseURL: "http://localhost:4000/v1",
 				APIKey:  "key",
 			},
+			Ollama: OllamaConfig{
+				BaseURL: "http://localhost:11434/v1",
+				APIKey:  "ollama",
+			},
 			OpenRouter: OpenRouterAIConfig{
 				BaseURL: "https://openrouter.ai/api/v1",
 				APIKey:  "key",
@@ -29,12 +33,17 @@ func validConfig() Config {
 	}
 }
 
-func TestValidateAcceptsLiteLLMAndOpenRouter(t *testing.T) {
+func TestValidateAcceptsSupportedProviders(t *testing.T) {
 	cfg := validConfig()
 	if err := cfg.Validate(); err != nil {
 		t.Fatalf("Validate litellm error = %v", err)
 	}
 
+	cfg.AI.Provider = "ollama"
+	if err := cfg.Validate(); err != nil {
+		t.Fatalf("Validate ollama error = %v", err)
+	}
+
 	cfg.AI.Provider = "openrouter"
 	if err := cfg.Validate(); err != nil {
 		t.Fatalf("Validate openrouter error = %v", err)