feat(tools): implement CRUD operations for thoughts and projects

* Add tools for creating, retrieving, updating, and deleting thoughts.
* Implement project management tools for creating and listing projects.
* Introduce linking functionality between thoughts.
* Add search and recall capabilities for thoughts based on semantic queries.
* Implement statistics and summarization tools for thought analysis.
* Create database migrations for thoughts, projects, and links.
* Add helper functions for UUID parsing and project resolution.

internal/config/validate_test.go

@@ -0,0 +1,60 @@
+package config
+
+import "testing"
+
+func validConfig() Config {
+	return Config{
+		Server: ServerConfig{Port: 8080},
+		MCP:    MCPConfig{Path: "/mcp"},
+		Auth: AuthConfig{
+			Keys: []APIKey{{ID: "test", Value: "secret"}},
+		},
+		Database: DatabaseConfig{URL: "postgres://example"},
+		AI: AIConfig{
+			Provider: "litellm",
+			Embeddings: AIEmbeddingConfig{
+				Dimensions: 1536,
+			},
+			LiteLLM: LiteLLMConfig{
+				BaseURL: "http://localhost:4000/v1",
+				APIKey:  "key",
+			},
+			OpenRouter: OpenRouterAIConfig{
+				BaseURL: "https://openrouter.ai/api/v1",
+				APIKey:  "key",
+			},
+		},
+		Search:  SearchConfig{DefaultLimit: 10, MaxLimit: 50},
+		Logging: LoggingConfig{Level: "info"},
+	}
+}
+
+func TestValidateAcceptsLiteLLMAndOpenRouter(t *testing.T) {
+	cfg := validConfig()
+	if err := cfg.Validate(); err != nil {
+		t.Fatalf("Validate litellm error = %v", err)
+	}
+
+	cfg.AI.Provider = "openrouter"
+	if err := cfg.Validate(); err != nil {
+		t.Fatalf("Validate openrouter error = %v", err)
+	}
+}
+
+func TestValidateRejectsInvalidProvider(t *testing.T) {
+	cfg := validConfig()
+	cfg.AI.Provider = "unknown"
+
+	if err := cfg.Validate(); err == nil {
+		t.Fatal("Validate() error = nil, want error for unsupported provider")
+	}
+}
+
+func TestValidateRejectsEmptyAuthKeyValue(t *testing.T) {
+	cfg := validConfig()
+	cfg.Auth.Keys[0].Value = ""
+
+	if err := cfg.Validate(); err == nil {
+		t.Fatal("Validate() error = nil, want error for empty auth key value")
+	}
+}