The six primitives that exist to stop unbounded memory growth were scattered
through `src/shared/` next to unrelated modules, so there was nowhere to state
when a new ceiling is warranted — and the last attempt at this work added many
that were not.
Moves them under `src/shared/memory-safety/` and adds a README carrying the
doctrine: bound at ingress, not in the interior; set limits far above real use;
decide overload behavior explicitly; and prefer fixing measured growth over
adding a speculative ceiling.
No behavior change. Pure move plus import-path updates across 48 files, with
`git mv` preserving history. Includes two `vi.mock` paths that had to move with
their modules — a mock left on the old path silently stops applying, which the
suite caught.
Verified: typecheck clean, oxlint 0 errors, 18,668 tests passing across
src/shared and src/main.
Neil