fix(data): fromData resets nonPersistent space to defaults

[krisnye]

Description

db.fromData() restored only the persistent side of the store and left the negative-ID nonPersistent space (nonPersistent resources + entities) holding the loading store's pre-load live values. This is inconsistent with db.reset(), which reverts nonPersistent state to its schema defaults.

Because nonPersistent data is never captured by toData() (only its archetype componentNames, never data), the only correct value after a load is the default. Leaving the stale live value leaks it across a same-instance load — e.g. a Save-As → Load in the same session keeping every pre-load blob: URL forever (the downstream FFP "video clips not visible after reopen" thumbnail bug).

Fix

core.fromData now resets the nonPersistent location table and zeroes nonPersistent archetype rows before restoring the persistent side (which is fully overwritten anyway). The store layer then re-seeds nonPersistent resource defaults via its existing rowCount === 0 re-init guard. This mirrors reset() exactly.

Why existing tests missed it

Every fromData test loaded a snapshot into a freshly-constructed store, whose nonPersistent resources were already at their defaults — so the assertions passed vacuously, not because fromData reset anything. Added red-green coverage that loads into a populated (non-fresh) store:

• a nonPersistent resource holding a non-default value reverts to default after load
• a nonPersistent entity present before the load is cleared

Version bumped to 0.9.78.

Testing

• vitest run --project node — 1343 tests pass; new populated-store cases are red without the fix, green with it.