[barfle]

A delayed CLI request or renewal could reload another account from the same saved file, retry the original action as that account, or overwrite a newer sign-in. Bind each client to an opaque local session identity; renewal retains that identity and explicit sign-in, key installation and sign-out replace it. Check ownership before admission, retry, persistence and response publication.

Use short cross-process file transactions and private atomic replacement, preserving concurrent renewal and independent preferences while refusing stale or conflicting writes. Persist an input-bound renewal recovery UUID before HTTP so competing processes and response-loss recovery reuse the same server request. Keep tunnel publishers on a separate credential-free Runtime client, pin recipients, and prevent netrc/session authentication from overriding selected proof. Primary sign-in uses an anonymous client and binds a new authenticated client only after commit.

Validation: 292 unit tests and 74 subtests pass in a clean installation using only declared dependencies, with the configured 100% coverage gate (cli.py and remote_access.py remain the existing exclusions). All 326 qualification contracts pass, including a local TCP bridge. Compile and five help commands pass with no external Click installed; configuration failures use supported Typer echo/Exit. All 15 packaged Python sources match the local private wheel. Real process tests cover competing sign-ins, shared recovery IDs and lock contention.

The initial CI exposed an undeclared Click import, now removed, and a cancelled macOS package job on a retired macos-14 runner. CI and the existing release-build workflow now select supported macos-15-intel; release triggers and qualification-only/publication rules are unchanged. Exact source ed2ce62 passed CI 42310201370: both Python unit jobs, Windows unit tests, all three compile/help/native TCP jobs, Windows MSI installation/uninstallation, macOS PKG installation/forwarding and Linux package installation/forwarding. No blind reruns or waived assertions.

Stacked on #78; merge only into the private codex/native-pkce-login qualification branch. Hold main merge and release for matching backend/client staging qualification and unchanged published agent campaigns. Actual server logout remains separate work pending the per-session/account-wide contract. No production, public package, installer feed or store release is dispatched.

Private qualification-only signed build 42310729728 was rejected before build steps by the release-signing environment, which permits only main and v* tags. The publication job was SKIPPED. Environment protections remain intact; no release tag or public distribution was used to bypass that restriction.