Rename smartrun to geniusrun throughout the codebase

Updates the Go module path, cmd/smartrund -> cmd/geniusrund, the
smartrun-dev skill, .gitignore, and every reference in docs/CLAUDE.md
to match.

backend/internal/api/api_test.go

@@ -13,16 +13,16 @@ import (
 	"testing"
 	"time"
 
-	"smartrun/backend/internal/garmin/mock"
-	"smartrun/backend/internal/store"
-	appsync "smartrun/backend/internal/sync"
+	"geniusrun/backend/internal/garmin/mock"
+	"geniusrun/backend/internal/store"
+	appsync "geniusrun/backend/internal/sync"
 )
 
 func newCtx() context.Context { return context.Background() }
 
 func newTestServer(t *testing.T) (*Server, *store.DB) {
 	t.Helper()
-	db, err := store.Open(filepath.Join(t.TempDir(), "smartrun_test.db"))
+	db, err := store.Open(filepath.Join(t.TempDir(), "geniusrun_test.db"))
 	if err != nil {
 		t.Fatalf("store.Open: %v", err)
 	}