canon is the single source of truth for the facts about the candidate's work. One file holds the experience, the projects, the skills and the boundaries, and every application the vault produces is built from it. Nothing is written into a pack that is not first true in canon, so a claim has exactly one place to be right and one place to be corrected.
The point of a single source is that a reference needs an owner. A loop cannot ask whether its own target is correct, and a drafting model certainly cannot be trusted to decide which facts about a person are real. So the facts are set by a human, edited by a human, and treated by everything downstream as given rather than negotiable. canon is the root the fast machinery is measured against, not a thing the machinery gets to revise to make its own job easier.
It is also why the vault stays private. canon is personal history, so it is gitignored and never leaves the machine. The engine that reads it, tailored, is open source; the facts it reads are not.