Changes touching this path

• Build loot burn: destroy + tombstone, no resurrection (#344) 0d1cc5af · dbf3dbe6…
• Authenticate the purge lane: a purge is a signed request (#503) A wire purge carried only an oid and yielded an unauthored tombstone, and stow honored it before storing objects -- so any authenticated pusher could destroy any oid across every tenant, needing no key, only the address. ADR 0038 already called a purge event a request asking cooperating relays and peers to destroy their copy. Cooperating meant nothing: loot honored anyone. The signature now says who is asking; a per-receiver policy decides whether to honor. Peers honor registered senders and quarantine strangers; relays honor their push allowlist. Local burn is untouched and needs no key -- only propagation requires a signature, so a keyless repo burns locally and refuses to propagate, explicitly. No global entitlement predicate exists: ChangeNode.tree is a full manifest and loot duplicate copies a tree address-for-address, so authored-a-change- referencing-this-oid is satisfiable by any cloner. Both withdrawn rules have regression tests. Format 9 to 10. A v10 reader parses a legacy purge lane and drops it, so no unsigned request is honored while the rest of a v9 bundle still decodes; an older client hard-fails on v10. Destruction is structurally unreachable without verification: HonoredBurn has a private field and authorize_burn is its only constructor. Both halves are signed, with domain-separated schemes -- without tags a maroon signature re-encodes byte-for-byte as a burn tombstone at path length 31. Maroon entitlement is an exact Manifest grantor join, and a grant only records a grantor when it actually installed a key, so a crafted grant cannot plant one for content you already hold. Closes #503. 913c5cc6 · dbf3dbe6…diff
• burn::Burn: one home for the burn/purge concept (#662) 8e7834a7 · dbf3dbe6…diff

Renames are not followed. loot's tree maps a path to an address, so a rename is a delete and an add. This list is the history of the name, not of the bytes.