What structural property is shared across the documented loss mechanisms?

The synthesis question §3.5 asks. §3 catalogues four mechanism categories — personnel turnover, physical/technical loss, funding termination, platform discontinuation — each with substantially different proximate causes. Q-0019 asks whether they share a structural property that the architectural argument can target.

The answer is C-0021: every loss mode reduces to single-copy dependency in a single failure domain. Each mechanism destroys a specific dataset only when that dataset exists in a single copy within a single failure domain; each is absorbed without permanent loss when independent copies exist across independent failure domains.

Q-0019 is the operational form of Q-0001 (architectural vs operational). It is the question whose answer is the architectural claim of the paper reduced to its operational form. The reduction from four mechanisms to a single property is what makes C-0001 a structural claim rather than a list of separate problems — and it is what justifies the architectural recommendation rather than four mechanism-specific procedural reforms.