feat(gui): add custom-shortcut Tap/Hold recorder to the button picker

[fahadjibransheikh]

Summary

• Action::CustomShortcut / Action::HoldShortcut and the KeyCombo parser already exist end-to-end in openlogi-core (config schema, IPC, agent runtime dispatch), but there was no way to reach either from a physical button binding — the catalog picker deliberately excludes both, and the only shortcut recorder in the app lives inside the Actions Ring slot editor.
• Adds a "Custom shortcut" section (Tap/Hold choice + free-text KeyCombo input) to the shared button-binding picker, so mouse buttons and the 5-direction gesture map (HapticPanel/GestureButton) can record a custom or held shortcut without hand-editing config.toml.
• Came up pairing a haptic-pad button with a third-party hold-a-shortcut launcher (e.g. Droppy's Ring) — that binding was only reachable by hand-editing the config file before this change.

Changes

• crates/openlogi-desktop/src/features/mouse/view.rs: MouseModelView gains shortcut_input/shortcut_hold fields (built the same way as the existing action_search), a set_shortcut_hold setter, and a localize_inputs helper (kept render() under the workspace's too_many_lines limit) that re-derives both inputs' placeholders on a live language switch.
• crates/openlogi-desktop/src/features/mouse/inspector.rs: ActionPickerContext carries the two new fields; the shared action_library() (used by the plain-button, inherited-gesture, and gesture-direction inspectors) gets a new custom_shortcut_editor section appended after the catalog list, committing through the existing on_pick: &PickFn — no new commit plumbing.
• crates/openlogi-ui/locales/*.toml (all 23): four new keys under [actions] — custom_shortcut, shortcut_placeholder, shortcut_hold, shortcut_tap — at the same position in every file. Non-English values are the English source text for now, per the i18n rule (Crowdin improves them later).

Testing

• cargo fmt --all -- --check — clean
• cargo clippy -p openlogi-desktop -p openlogi-ui --all-targets -- -D warnings — clean (one real finding along the way: MouseModelView::render crossed the 100-line too_many_lines limit after adding a placeholder call; fixed by extracting localize_inputs rather than suppressing the lint)
• cargo test -p openlogi-desktop -p openlogi-ui — 221 tests pass, including locale_files_have_the_same_keys (catalog parity) and services::i18n::tests::typed_translation_keys_resolve
• GUI exercised end-to-end against openlogi-agent-mock (real hardware wasn't reachable for this dev build — TCC permissions for an ad-hoc-signed bundle, a local dev-environment limitation, not something this diff touches): bound a plain button (Middle Click) to Hold+chord and a gesture-direction row (the same code path HapticPanel/GestureButton use) to Tap+chord, both committed and rendered correctly and distinctly.
• Not runtime-tested on real hardware — the mock-agent verification above exercises the same code path, but real-device confirmation is the maintainer's call per AGENTS.md. Happy to attach screenshots from the mock-agent verification in a comment if useful.

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; no actionable issues remain in the reviewed changes.

Summary

The picker now lets users choose Tap or Hold for a custom shortcut.

• Mouse buttons and gestures can save custom shortcuts as taps or holds.

No new actionable issues were found in the changes since the previous review.

_{Reviews (5) · Last reviewed commit: "fix(gui): model shortcut mode as an enum" · Reviewed by Greptile}

[fahadjibransheikh]

Fixed both Greptile findings in 3936e3e:

• Shortcut state persists: shortcut_input/shortcut_hold now reset in the same opening-branch of selection_card's click handler that already clears action_search, so switching to a different button/gesture-direction no longer shows a stale draft.
• Invalid input fails silently: Add is now disabled while the current text doesn't parse as a KeyCombo (covers empty input, modifier-only combos, unknown keys, malformed separators). Needed a live-updating subscription on shortcut_input (mirroring the existing one on action_search) so the disabled state tracks each keystroke rather than only the last unrelated re-render.

cargo fmt --check, cargo clippy -p openlogi-desktop --all-targets -- -D warnings, and cargo test -p openlogi-desktop (218 tests) all green on the new commit.