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/observability/http_test.go

@@ -0,0 +1,59 @@
+package observability
+
+import (
+	"io"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestRequestIDSetsHeaderAndContext(t *testing.T) {
+	handler := RequestID()(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if got := RequestIDFromContext(r.Context()); got == "" {
+			t.Fatal("RequestIDFromContext() = empty, want non-empty")
+		}
+		w.WriteHeader(http.StatusNoContent)
+	}))
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	if rec.Header().Get("X-Request-Id") == "" {
+		t.Fatal("X-Request-Id header = empty, want non-empty")
+	}
+}
+
+func TestTimeoutAddsContextDeadline(t *testing.T) {
+	handler := Timeout(50 * time.Millisecond)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if _, ok := r.Context().Deadline(); !ok {
+			t.Fatal("context deadline missing")
+		}
+		w.WriteHeader(http.StatusOK)
+	}))
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+}
+
+func TestRecoverHandlesPanic(t *testing.T) {
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	handler := Recover(logger)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		panic("boom")
+	}))
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusInternalServerError {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusInternalServerError)
+	}
+}