feat(linux): launch_at_login + input device access permission check

[cserby]

Summary

• launch_at_login on Linux — writes/removes a systemd user unit at $XDG_CONFIG_HOME/systemd/user/openlogi-agent.service. Mirrors the macOS LaunchAgent behaviour exactly: Restart=on-failure (crash respawns; clean exit(0) stays stopped), WantedBy=graphical-session.target (takes effect at next login). Unit content is compared before writing (idempotent). systemctl --user enable/disable is best-effort — failures are logged, not propagated.
• Input device access permission check on Linux — Settings → Permissions now shows a Linux-specific row ("Input device access") backed by probes of /dev/uinput (write) and /dev/hidraw* (read/write, Logitech vendor verified numerically from sysfs HID_ID). Returns Granted / Denied / Unknown (unknown = uinput accessible but no Logitech device connected yet). Description is shown only when access is not yet granted.
• macOS-only UI hidden on Linux — accessibility footer, permission "Open" button, and "log in to macOS" copy are all gated to macOS.

Test plan

• cargo test -p openlogi-agent -p openlogi-gui passes on Linux (7 new unit tests in launch_agent.rs, 4 in permissions.rs)
• cargo clippy --workspace --all-targets -- -D warnings clean
• cargo fmt --check clean
• Toggle "Launch at login" → ~/.config/systemd/user/openlogi-agent.service appears; systemctl --user is-enabled openlogi-agent reports enabled; toggle off → file removed, disabled
• Settings → Permissions shows "Granted" with udev rules installed; "Not granted" without
• No macOS-specific text or buttons visible in Linux GUI build

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

Adds Linux support for two previously macOS-only features: launch_at_login (writes/removes a systemd user unit and calls systemctl --user enable/disable) and an input-device permission probe (/dev/uinput write + /dev/hidraw* read/write via sysfs vendor check). macOS-only UI elements (accessibility footer, "Open" button, platform copy) are correctly gated behind #[cfg(target_os = \"macos\")].

• launch_agent.rs: New reconcile_linux path generates an idiomatic systemd unit file with correct Rust string-continuation formatting, idempotent content comparison, and best-effort systemctl calls. The escape_systemd_exec helper handles %, $, spaces, and \", but omits \\ (backslash), which systemd processes as an escape character in ExecStart.
• permissions.rs: probe_uinput + probe_logitech_hidraw implement the tri-state Granted/Denied/Unknown classification; the pure classify() function is extracted and covered by four unit tests. The probes are called inside a SettingField::render callback, matching the existing macOS pattern but at higher per-frame syscall cost.
• Locale files: 22 locales updated; most non-CJK languages carry the English fallback for "Input device access" (intentional placeholder).

Confidence Score: 5/5

Safe to merge; all changes are well-structured Linux additions with no regressions to existing macOS/Windows paths.

The Linux systemd and permission-probe implementations are logically correct and covered by 11 new unit tests. The two observations (incomplete backslash escaping in escape_systemd_exec and per-render filesystem work in probe_logitech_hidraw) are quality improvements rather than current defects — backslash in an executable path is essentially impossible in practice, and the performance concern only manifests while the Settings window is open.

crates/openlogi-agent/src/launch_agent.rs — the escape_systemd_exec helper

Important Files Changed

Filename	Overview
crates/openlogi-agent/src/launch_agent.rs	Adds Linux systemd user-unit reconcile path alongside the existing macOS/Windows implementations; escaping handles %, $, spaces and quotes but omits backslash, which systemd interprets as an escape character in ExecStart
crates/openlogi-gui/src/platform/permissions.rs	Adds Linux-specific input device access probe (uinput + hidraw); classify() logic is correct and well-tested; probe_logitech_hidraw does filesystem work per render call which matches the existing macOS pattern
crates/openlogi-gui/src/windows/settings.rs	Gates macOS-only UI (accessibility footer, Open button, platform copy) behind cfg, adds Linux-specific permissions item; clean split from the original shared function
crates/openlogi-core/src/paths.rs	Extracts xdg_config_home() so systemd unit path can reuse the XDG_CONFIG_HOME resolution without the openlogi-specific subdirectory; correct refactor
crates/openlogi-gui/src/app.rs	Correctly gates accessibility_status() behind #[cfg(target_os = "macos")] so the footer renders an empty div on Linux

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A([reconcile enabled]) --> B{unit_path OK?}
    B -- Err --> Z([return Err])
    B -- Ok --> C{current_exe OK?}
    C -- Err --> Z
    C -- Ok --> D[render desired unit content\nor None if !enabled]
    D --> E[read current unit file\nok = Some, missing = None]
    E --> F{desired vs current}
    F -- Same content --> G([debug: already current])
    F -- Want to write --> H[create_dir_all parent]
    H --> I[fs::write unit file]
    I --> J[systemctl --user daemon-reload\nbest-effort]
    J --> K[systemctl --user enable\nbest-effort]
    K --> G
    F -- Want to remove --> L[systemctl --user disable\nbest-effort]
    L --> M[fs::remove_file]
    M -- Err --> Z
    M -- Ok --> N[systemctl --user daemon-reload\nbest-effort]
    N --> G
    F -- Both absent --> O([debug: already absent])

Loading

_{Reviews (10): Last reviewed commit: "fix(gui): gate platform-specific imports..." | Re-trigger Greptile}