fix(desktop): gate codex-acp on a minimum supported version

[wpfleger96]

The codex adapter version gate accepted any major >= 1, so a 1.x codex-acp older than the version that fixes outbound relay access for buzz CLI subprocesses classified as Available and was never offered a reinstall. Only the 0.16.x @zed-industries/codex-acp adapter — which fails --version outright — was caught.

probe_codex_acp_version now returns the full (major, minor, patch) triple and codex_adapter_availability compares it against a new MIN_CODEX_ACP_VERSION floor of 1.1.7, the current npm latest. An adapter below the floor classifies as AdapterOutdated, which routes it through the existing uninstall-then-install reinstall plan.

The parse requires exactly three numeric dot-separated components. Partial versions (1.2) and prerelease tags (1.2.0-rc1) return None and therefore classify as AdapterOutdated — a version Buzz cannot compare against the floor fails closed, offering a reinstall rather than running an adapter of unknown vintage. Both the floor's bump policy and the strict-parse behavior are stated in doc comments rather than left implicit.

Supersedes #3097 by @Bharathchinneni, whose semver floor and behavior tests this carries. That PR could not land as written: the two probe_codex_acp_major_version compatibility wrappers it kept had no non-test callers, which is a hard clippy -D warnings failure. The wrappers are deleted here and their call sites collapsed onto probe_codex_acp_version.