mount: fix iPod automount (lsblk flags + udisks suffixed paths)

Two bugs kept the connected iPod from being auto-mounted:

- `lsblk -o PATH,LABEL -n -l -P` is invalid (--pairs and --list are
  mutually exclusive), so device lookup by label always failed with
  "no block device found" — a regression from the earlier parse fix.
  Drop -l.
- udisks mounted the iPod volume at /media/sebastian/IPOD1 because the
  configured directory /media/sebastian/IPOD already exists, so even a
  resolved device failed with AlreadyMounted. The configured mount point
  is now treated as a hint: mounted_path_for() resolves an exact mount or
  the lowest-numbered udisks-suffixed sibling (IPOD → IPOD1) from
  /proc/self/mountinfo, and the sync destination, storage stats, settings
  display and fatsort resolution all use the real mount.

Also harden fatsort: resolve_fatsort_target now refuses to run when the
path is not a mount point, so findmnt can never fall back to the root
filesystem's block device.

Verified on the connected iPod: mounted_path_for → IPOD1,
resolve_block_device → /dev/sdb2, mount_device → "already mounted at
/media/sebastian/IPOD1", UI shows ● mounted with 9.7 GiB free · 92% and
mount point ✓ /media/sebastian/IPOD1.

Bump to 0.3.3.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "dap-tui"
-version = "0.3.2"
+version = "0.3.3"
 edition = "2021"
 description = "Device sync for portable players — TUI edition (ratatui)"
 license = "MIT"