b2ca63ee9f
Closes the agent half of R-39's fleet fix. Requires hub >=0.68.0 for the re-arm signal; that hub is safe for 0.90.0 agents (unknown key dropped), so it deploys first. Three compounding defects let a box report `applied` while every PBS request 401'd: 1. The re-key was INVISIBLE. An ep0 re-issue rotates the secret of an existing token, so token_id/fingerprint/datastore/namespace come back byte-identical and the descriptor content hash never moved — the converged agent short-circuited and never consumed the fresh secret. WirePBSDR.SecretGeneration (field-exact with the hub) is what moves the hash now, because descriptorHash marshals this struct. 2. The agent could not READ its own credential. It writes /etc/pve/priv/storage/<id>.pw through the root wrapper, but that dir is 0700 root:www-data and the wrapper had no read verb — so the target resolver got "permission denied" every cycle, warned, and skipped. The one loop that could have caught the 401 was blind BY CONSTRUCTION. Adds a narrow `read` verb (+ exactly one sudoers line, + a pbsdr-read capability row): one secret to stdout, no network, no mutation, never in argv (sudo logs argv), traversal refused by the id grammar, the dir allowlist AND a resolved-path prefix assertion. 3. Nothing probed AUTHENTICATION. pbs.ProbeAuth (GET /version + an ErrUnauthorized sentinel) runs on the 15-minute collect path and its verdict becomes a loud `auth_failed` the hub escalates to a fresh mint. /version needs no datastore, namespace or privilege, so a 401 means the CREDENTIAL is bad; 403 is deliberately NOT treated as unauthorized, since re-keying a too-narrow token would mint forever without fixing anything. A transport error is UNKNOWN, never a rejection — otherwise every network blip burns a credential. Recovery self-clears. R-50b(a): the report now carries the installed wrapper's sha256 so drift against the vouched manifest value is answerable. Empty = unknown, never drift. Three red-proofs, all at the assertion level. Removing SecretGeneration fails the re-arm test with "consume calls=1, want 2". Swallowing the probe result leaves State:applied AuthFailed:false — the July-18 shape exactly. Notably, deleting the wrapper's id charset guard alone does NOT open a traversal hole (readlink + the prefix assertion still catch it), so the isolating red-proof removes BOTH and shows the out-of-tree secret printed — the layering is real, and a single-guard red-proof would have passed vacuously.