update where shell starts and add override -home setting

internals/handlers.go

@@ -374,7 +374,7 @@ func handleUpload(w http.ResponseWriter, r *http.Request) {
 
 	destDir := strings.TrimSpace(r.FormValue("dest"))
 	if destDir == "" {
-		destDir = initialCwd
+		destDir = shellHome
 	}
 	destPath := filepath.Join(filepath.Clean(destDir), filepath.Base(header.Filename))
 
@@ -400,7 +400,7 @@ func handleDownload(w http.ResponseWriter, r *http.Request) {
 	}
 	full := filepath.Clean(path)
 	if !filepath.IsAbs(full) {
-		full = filepath.Join(initialCwd, full)
+		full = filepath.Join(shellHome, full)
 	}
 	if _, err := os.Stat(full); err != nil {
 		http.Error(w, "file not found", http.StatusNotFound)