[richardgetz]

This change clears the active dependency findings reported by cargo-deny without changing its policy.

Finding	Remediation
RUSTSEC-2026-0338, -0339, -0340, -0341, -0342	Resolve quinn-proto to 0.11.18, the patched release used by the tunnel dependency path.
RUSTSEC-2026-0346, -0347, -0348, -0349	Resolve rustls to 0.23.46.
RUSTSEC-2026-0367, -0368, -0369	Upgrade zip to 9.0.4 and adapt the affected archive consumers.
RUSTSEC-2026-0370, -0371, -0372	Move the TUI to zbus 6 and switch keyring’s Linux Secret Service backend to its synchronous persistent implementation, removing the active zbus 4 path.
RUSTSEC-2024-0449	Replace serde_yaml’s unmaintained unsafe-libyaml implementation with the maintained yaml_serde package via the existing serde_yaml import name.

The keyring migration keeps the current Linux native backend selection, keyutils plus Secret Service persistence, and its existing fallback semantics. It retains the same service, account, target and application identifiers, so existing stored records continue to be addressed through the same keyring interface. The macOS Keychain ACL implementation and platform selection are unchanged. No user credentials were read or modified.

Validation:

• Local cargo deny --log-level warn --manifest-path ./codex-rs/Cargo.toml --all-features check — advisories, bans, licenses and sources all pass.
• GitHub cargo-deny job 117452728877 on this PR — pass.
• just test -p codex-keyring-store preserves_typed_causes_without_guessing_from_messages — 1 passed on macOS.
• just test -p codex-tui motion::tests — 2 passed on macOS.
• just test -p codex-core-plugins curated_plugin_zip_extraction_strips_privileged_permission_bits — 1 passed, 479 skipped on macOS; compiled the updated ZIP consumer and exercised Unix privileged-bit stripping.
• Linux cargo check -p codex-keyring-store -p codex-rmcp-client -p codex-tui passed on Ubuntu 24.04 with Rust 1.95.0 in run 39053341869. The job later stopped at a missing nextest installation before running tests; the compile/check step itself passed.
• The focused Linux tests passed on Ubuntu 24.04 in run 39054658890: keyring typed-error classification (1 passed, 6 skipped) and TUI motion behavior (2 passed, 6066 skipped). The run installed pinned cargo-nextest 0.9.103 and verified its checksum. Nextest also reported that .config/nextest.toml key profile.local.inherits is unknown to this version; this nonfatal warning did not prevent either selected test from running.
• These Linux runs used an isolated proof-only branch based on this PR’s source SHA 540bbabc1cbf0a20d4cf4bc790c0ae5b257e4731. The source-parity gate passed and confirmed the proof branch differs from the PR source only in the existing .github/workflows/rust-ci.yml; that temporary proof change is not part of this PR. The proof job used one Ubuntu runner with contents: read, no secrets and no matrix.
• just bazel-lock-update, final just fmt, and git diff --check origin/stable passed.

The TUI adapter uses zbus 6’s OwnedVariant API. Fork Delta Inventory: no entry is needed; this change adds no fork-only behavior. Workflow cleanup PR #197 remains separate.