dig-urn-protocol 0.1.0

Canonical DIG Network content-addressing + server-untrusted verification contract: the urn:dig: scheme and byte-level grammar (parse / canonical / SHA-256 retrieval-key), the UrnResolver resolution interface, and the fail-closed browser content-verification contract (gate-then-decrypt, u64-bounded chunk split, rootless-URN rejection on the blind tier) over injected merkle/AES primitives.