refactor: delegate -l output to findmnt

The custom one-alias-per-line output was useless — no mountpoint, no
source, no options. Reinventing a table format when findmnt from
util-linux already produces a familiar fuse.sshfs view was the wrong
call. -l now shells out to findmnt -t fuse.sshfs.

README.md

@@ -22,6 +22,7 @@ install -Dm755 sshfsc /usr/local/bin/sshfsc
 # Dependencies
 
 - [SSHFS](https://wiki.archlinux.org/title/SSHFS)
+- `findmnt` from `util-linux` (for `-l`)
 - [Go](https://wiki.archlinux.org/title/Go) >= 1.25 (build-time)
 
 # Usage
@@ -39,7 +40,7 @@ sshfsc -l              # list active mounts
 | `-e` | open mountpoint in your editor |
 | `-v` | verbose: print resolved ssh_config fields (HostName, User, Port, IdentityFile) |
 | `-r`, `--remote-dir <path>` | remote directory to mount (default: remote home) |
-| `-l` | list active mounts under `$XDG_RUNTIME_DIR/sshfs/` and exit |
+| `-l` | list active fuse.sshfs mounts via `findmnt` and exit |
 | `-u` | unmount the given `<Host>` and exit (mutually exclusive with `-l`) |
 
 By default only the resolved mount path is printed. Use `-v` for the full