route_load was a stub response over the most destructive operation in the
server: engram_load resets the store before parsing, so a readable-but-
malformed snapshot left a hollow graph and the route answered {"ok":true}.
With 37GB of stale dated snapshots in the data dir as restore targets, that
is a live risk. Now returns the real return value plus node/edge counts and
an explicit hollow flag.
route_save discarded engram_save's return the same way; persist_canonical
returned a hardcoded 1, making 'let saved: Int = persist_canonical()' a dead
variable at six durable write paths.
will.anderson
791b0880b7