Configurable list columns via header right-click

Native checkable menu on the column headers toggles Size, Modified,
Kind, Rights, Owner and Group (persisted, both panels). Owner/group
come from the ls-style SFTP longname remotely and cached uid/gid
lookups locally (POSIX; undefined on Windows). All columns sort.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/bun/fs/sftp.ts

@@ -10,6 +10,18 @@ const S_IFMT = 0o170000;
 const S_IFDIR = 0o040000;
 const S_IFLNK = 0o120000;
 
+/**
+ * Owner/group from the ls-style longname openssh sends with each entry
+ * ("-rw-r--r--  1 root wheel  1024 Jan  1 00:00 name"). Servers aren't
+ * required to use this format — bail to undefined when it doesn't parse.
+ */
+function ownerFromLongname(longname: string | undefined): { owner?: string; group?: string } {
+	if (!longname || !/^[-dlbcps]/.test(longname)) return {};
+	const fields = longname.split(/\s+/);
+	if (fields.length < 5) return {};
+	return { owner: fields[2], group: fields[3] };
+}
+
 function typeFromMode(mode: number): EntryType {
 	const fmt = mode & S_IFMT;
 	if (fmt === S_IFDIR) return "dir";
@@ -132,6 +144,7 @@ export class SftpProvider implements FileSystemProvider {
 							size: e.attrs.size,
 							mtime: e.attrs.mtime * 1000, // sftp attrs are seconds
 							mode: e.attrs.mode & 0o7777,
+							...ownerFromLongname(e.longname),
 						})),
 				);
 			});