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/cmd/seedsample/main.go

@@ -12,14 +12,14 @@ import (
 	"log"
 	"time"
 
-	"smartrun/backend/internal/classify"
-	"smartrun/backend/internal/garmin/mock"
-	"smartrun/backend/internal/store"
-	appsync "smartrun/backend/internal/sync"
+	"geniusrun/backend/internal/classify"
+	"geniusrun/backend/internal/garmin/mock"
+	"geniusrun/backend/internal/store"
+	appsync "geniusrun/backend/internal/sync"
 )
 
 func main() {
-	dbPath := flag.String("db", "smartrun_sample.db", "path to the SQLite database to seed")
+	dbPath := flag.String("db", "geniusrun_sample.db", "path to the SQLite database to seed")
 	flag.Parse()
 
 	ctx := context.Background()