Spoolman resolves a spool's tare from the spool, then the filament, then
the vendor's empty_spool_weight. Bambuddy skipped the vendor and fell
back to 250 g, so weighing a spool whose tare was set only on its vendor
gave the wrong remaining weight. The inventory weigh action, the
SpoolBuddy scale and the displayed core weight now share one lookup, and
"keep old weight" on a filament change stamps a vendor-inherited tare.
feat(spoolman-inventory): squashed feature work for rebase onto dev
Squashed all commits from feature/spoolman-inventory-ui onto a single commit
to enable a clean rebase onto dev. Original per-commit history preserved at
backup tag backup/spoolman-inventory-ui-prerebase-20260507-105721.
feat(spoolman-inventory): squashed feature work for rebase onto dev
Squashed all commits from feature/spoolman-inventory-ui onto a single commit
to enable a clean rebase onto dev. Original per-commit history preserved at
backup tag backup/spoolman-inventory-ui-prerebase-20260507-105721.