feat: add copy mode save

Adds a 'copy' mode to showSaveFilePicker. In this mode, a source file is
copied to the target file. The file may not exist in another apps
AppData directory. Unlike the 'move' mode, the file can be outside of
the app's AppData directory (a "user" file); in this situation the user
will be prompted to grant permission for the copy action. The app will
have access to the newly-created copy.

src/gui/src/IPC.js

@@ -1382,32 +1382,68 @@ const ipc_listener = async (event, handled) => {
             $(el_filedialog_window).find('.window-disable-mask, .busy-indicator').hide();
         };
         
-        const handle_move_save = async ({ source_path, target_path, el_filedialog_window }) => {
+        const handle_move_save = async ({
+            // when 'source_path' has a value, 'save_type' is checked to determine
+            // if a fs.move() or fs.copy() needs to be performed.
+            save_type,
+            
+            source_path, target_path, el_filedialog_window,
+        }) => {
             // source path must be in appdata directory
             const stat_info = await puter.fs.stat(source_path);
-            if ( ! stat_info.appdata_app ) {
-                await puter.ui.alert(`the app ${app_uuid} attempted to ` +
-                    `move data owned by the user illegaly`);
-                return;
+            if ( ! stat_info.appdata_app || stat_info.appdata_app !== app_uuid ) {
+                const source_file_owner = stat_info?.appdata_app ?? 'the user';
+                if ( stat_info.appdata_app && stat_info.appdata_app !== app_uuid ) {
+                    await UIAlert({
+                        message: `apps are prohibited from accessing AppData of other apps`
+                    });
+                    return;
+                }
+                if ( save_type === 'move' ) {
+                    await UIAlert({
+                        message: `the app <b>${app_name}</b> tried to illegally move a file owned by ${source_file_owner}`,
+                    });
+                    return;
+                }
+                
+                const alert_resp = await UIAlert({
+                    message: `the app ${app_name} is trying to copy ${source_path}; is this okay?`,
+                    buttons: [
+                        {
+                            label: i18n('yes'),
+                            value: true,
+                            type: 'primary',
+                        },
+                        {
+                            label: i18n('no'),
+                            value: false,
+                            type: 'secondary',
+                        },
+                    ]
+                });
+
+                // `alert_resp` will be `"false"`, but this check is forward-compatible
+                // with a version of UIAlert that returns `false`.
+                if ( ! alert_resp || alert_resp === 'false' ) return;
             }
             
-            if ( stat_info.appdata_app !== app_uuid ) {
-                await puter.ui.alert(`the app ${app_uuid} attempted to ` +
-                    `move data owned by ${stat_info.appdata_app}`);
-                return;
-            }
-            
-            console.log('supposedly we\'re writing this file now');
-            
             let node;
             const written = await window.handle_same_name_exists({
                 action: async ({ overwrite }) => {
                     if ( overwrite ) {
                         await puter.fs.delete(target_path);
                     }
-                    await puter.fs.move(source_path, target_path);
+                    
+                    if ( save_type === 'copy' ) {
+                        const target_dir = path.dirname(target_path);
+                        const new_name = path.basename(target_path);
+                        await puter.fs.copy(source_path, target_dir, {
+                            newName: new_name,
+                        });
+                    } else {
+                        await puter.fs.move(source_path, target_path);
+                    }
                     node = await puter.fs.stat(target_path);
-                    console.log('the move operation just happened', { node });
                 },
                 parent_uuid: $(el_filedialog_window).attr('data-element_uuid'),
             });
@@ -1441,6 +1477,7 @@ const ipc_listener = async (event, handled) => {
                     done = await handle_url_save({ target_path });
                 } else if ( event.data.source_path ) {
                     done = await handle_move_save({
+                        save_type: event.data.save_type,
                         source_path: event.data.source_path,
                         target_path,
                     });

src/puter-js/src/modules/UI.js

@@ -735,13 +735,14 @@ class UI extends EventListener {
                 type = 'url';
             }
             const url = type === 'url' ? content.toString() : undefined;
-            const source_path = type === 'move' ? content : undefined;
-
+            const source_path = ['move','copy'].includes(type) ? content : undefined;
+            
             if(this.env === 'app'){
                 this.messageTarget?.postMessage({
                     msg: "showSaveFilePicker",
                     appInstanceID: this.appInstanceID,
                     content: url ? undefined : content,
+                    save_type: type,
                     url,
                     source_path,
                     suggestedName: suggestedName ?? '',