On first launch (no data yet, no portable dir, no pointer file),
the wizard now shows a new step-0 screen asking where to store
wallets, config and certificates.
AppPaths changes:
- DefaultDataRoot() → ~/.PalladiumWallet (home, always writable)
- IsDataLocationConfigured() → true when portable / override / pointer
already written / legacy or default already has data
- ConfigureDataLocation(root) writes a bootstrap pointer file and
creates the directory
- DataRoot() resolution order: override → portable → pointer → legacy
(has data) → default
ViewModel: new StepDataLocation step, UseDefaultDataLocationCommand,
ApplyDataLocation(root) (also called from View's folder picker).
View: new wizard panel with description, default-path display, two
buttons (use default / choose folder); folder picker via
StorageProvider.OpenFolderPickerAsync.
Loc: add wiz.data.* keys (6 languages); fix fallback language "it"→"en";
update test assertion accordingly.
davide
f3bf4cf94a