Sync embedded computer use to v0.2.9

[avifenesh]

Summary

• sync the embedded codex-computer-use-linux copy from the current upstream baseline (0.2.6-linux-alpha1) through the standalone computer-use-linux v0.2.9 release
• preserve Codex-specific binary/tool/env identity while taking the standalone v0.2.7/v0.2.8/v0.2.9 behavior deltas
• port the v0.2.9 GTK4 accessibility fix so Nautilus/Text Editor/baobab-style apps read via destination-pinned AT-SPI proxies instead of the P2P no-destination fallback

Refs agent-sh/computer-use-linux#33
Refs agent-sh/computer-use-linux#34

Release/User-visible delta

• Embedded version parity moves to 0.2.9-linux-alpha1 in Cargo.toml, Cargo.lock, and the MCP tool handler literal.
• GTK4 app accessibility trees now return real application/window nodes instead of the old empty role: unknown, child_count: 0 result when the app does not expose GetApplicationBusAddress.
• Prior unpublished embedded deltas from v0.2.7/v0.2.8 remain included: target/input/backend fixes, COSMIC helper packaging, and the registry cosmic-protocols alignment used by the embedded build.

Validation

• cargo fmt --check -p codex-computer-use-linux
• git diff --check
• cargo check -p codex-computer-use-linux --all-targets
• cargo test -p codex-computer-use-linux
• cargo clippy -p codex-computer-use-linux --all-targets -- -D warnings
• cargo build -p codex-computer-use-linux
• node /home/avifenesh/projects/computer-use-linux/scripts/zod-check/check.mjs --command target/debug/codex-computer-use-linux
• live GTK4 probe: launched Nautilus and verified target/debug/codex-computer-use-linux state nautilus returned org.gnome.Nautilus as an application root with child_count: 1 and a window node named tmp with action metadata

[avifenesh]

This is an auto review done by revuto.

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Reviewed the v0.2.9 embedded computer-use sync. The async migration (ydotool/zbus/spawn_blocking), the GTK4 AT-SPI as_accessible_proxy destination-pinning fix, the cosmic-protocols move to crates.io (with matching flake.nix outputHashes removal — no git+ sources remain in Cargo.lock), the new codex-computer-use-cosmic bin (present on disk and wired into flake.nix install + Cargo.toml), and the relative-click bounds clamping all check out. The KDE clipboard path keeps a ydotool fallback (P14) and treats restore-after-paste failure as a warning, not an error (P15). One concern below.

[avifenesh]

This is an auto review done by revuto.

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This test mutates the process-global YDOTOOL_SOCKET env var with set_var/remove_var and restores it manually. Per repo convention (P12), env-var mutation in computer-use tests must use a Drop-based RAII guard, not manual save/restore: if explicit_ydotool_socket() or the assertion panics, the restore lines never run and the var leaks into other tests. Concretely, ydotool_socket_selection_skips_unconnectable_candidates/accepts_datagram_socket and the backend-preference helpers (should_prefer_*_text_backend) all read YDOTOOL_SOCKET via ydotool_socket(), and Rust runs tests in parallel by default — a leaked /does/not/exist.sock value can flip their behavior nondeterministically. Wrap the save/set/restore in an RAII guard so the original value is restored on every exit path.

[ilysenko]

Reviewed current head 93b714f after the env-var guard cleanup. Local validation: cargo fmt --check -p codex-computer-use-linux, cargo test -p codex-computer-use-linux, git diff --check. No blockers found.