Two consecutive plates of the same model would create the second print's
archive with the first plate's metadata: subtask_name lags across the
boundary while gcode_file is fresh, so the FTP candidate list (built
from subtask_name first) lands on the previous plate's still-resident
upload. The 3MF parser then locks the wrong _plate_index, name, time
estimate, and per-slot filament data into the archive at creation.
Fix peeks the downloaded 3MF's slice_info plate index, compares against
parse_plate_id(filename) (the plate parsed from /Metadata/plate_N.gcode,
which always reflects what's running), and on mismatch retries FTP with
swap_plate_suffix(subtask_name, expected_plate) — handling both the
spaced "Plate N" and underscored "_plate_N" suffix forms seen in real
subtask_names. If the retry finds a matching 3MF, the wrong file is
dropped and the corrected one feeds the archive; if no match is found
(or no swap is possible) the wrong file is dropped and the existing
no-3MF fallback creates an archive whose name reflects the right plate.
The validation only runs when parse_plate_id() returns a value, so
single-plate / cloud-named / non-Bambu jobs are unaffected.
17 new unit tests in test_archive_plate_validation.py cover both helpers:
plate-index peek across malformed / missing / non-integer / non-zip
inputs, and the suffix swap across both casings, the underscored form,
case-insensitive matching, and rejection of names without a recognised
suffix.
