Closes #54.

Paired implementation: compoundingtech/pty#128, the selected issue #126 protocol, now merged.

Summary

Rewrites the deterministic, model-free pty-live-recovery cell for PTY PR #128’s authenticated snapshot/revision contract. This is a held-out protocol rewrite, not a metadata-only retarget of the incompatible, superseded PR #127 oracle.

The cell uses only eval-owned synthetic PTY roots and providers. It proves:

• the exact merged PTY source and built CLI/server artifacts;
• pty recover <name> --snapshot <metadata.json> as the explicit surface;
• complete private-root capability fields for protocol, secret, process-start token, launch identity, root/recovery-directory identity, and signed metadata revision;
• stable daemon PID, generation, process-start token, launch identity, attached client, and provider across recovery;
• secret and revision rotation after recovery;
• fresh-client attachability and exactly one provider launch plus one session_start;
• replay refusal after rotation;
• stale pre-tag snapshot refusal without metadata rollback;
• secret-tampered snapshot refusal without registry publication;
• fail-closed root and .recovery permission downgrades before request/result, lock, socket, PID, or metadata publication;
• unsupported-daemon refusal while the original daemon stays alive; and
• cleanup limited to captured synthetic daemon PIDs and exact eval roots.

Exact dependency

PTY PR #128 final reviewed head 9ad3a4368027d8a9e78a22319615a3ab837347e1 was squash-merged as exact source 9eb958c5aae026d5c05690ab72b528662c55708d.

The squash landed on newer PTY main, so the lockfile and launcher remain identical while the compiled CLI/server digests correctly incorporate intervening merged work. Local exact-merged-source build provenance:

• package lock SHA256 43189b5b5b1d560be4b9102d2ed0793d89b9b01dbb3bbd976948f10c6669118d
• CLI launcher SHA256 3c3d655b713a6e1a40309eb1b45bb75a023e87dc6391f7dbaa54cefc3efb49ab
• compiled CLI SHA256 46285f9cb0212751ccc8344ba821038643c589c1b31a62cfd4354a5b56d2c5c3
• compiled server SHA256 f7ec154a8f968077c19a3affb5c08bed101fc045fa53cce64178f5512c30711b

This is exact merged-source evidence, not a published PTY release artifact.

Review-red closure

The predecessor cleanup could ignore a daemon termination timeout and prove only that registry roots were removed. Cleanup now binds every captured PID to its Linux process-start token, sends bounded TERM, uses bounded KILL only while that exact captured identity remains alive, and fails if any tracked identity survives. A TERM-resistant synthetic sentinel forces the KILL path on every green run. The judge requires the receipt’s allTrackedDaemonsDead fact, a positive captured-daemon count, and a positive fallback count in addition to root removal.

Validation

At exact eval head c595716794de7d027b9e0215ca0d34ae573a5981, after normal follow-up commits only:

• frozen old PR #127 oracle against final PR #128: expected RED, 0 PASS / 8 FAIL / 8 gating judges
• merged-source pty-live-recovery: 11 PASS / 0 FAIL / 11 gating judges
• cleanup receipt: 5 captured daemons, 6 tracked processes, all tracked identities dead, 1 forced KILL fallback, both exact roots absent; receipt SHA256 9e1c4005c0236e82deaee8b421cce8edf314d5f652d6830708fbd9d73ca0c117
• complete 59-cell model-free corpus preflight: PASS on published st2 0fed14bb5653b67e1d64f1199e240c4c5c612bf7, binary SHA256 d61d12b2b1189a391c196ca28f8f4ba69072d14fcbad2571fc29db1f250f4eed
• 224 shell files parse, 109 KDL files parse, 59 maintained evals load semantically, 11 nested fleet catalogs validate strictly, generated catalog and all model-free policy/history/VRS/cleanup gates: PASS
• zero model/provider calls and no residual eval-owned PTY roots

No production recovery, provider call, merge of this PR, or deployment was performed.