fix: hotplug-driven inventory and phantom device-card suppression

[davidbudnick]

Context

Stale device cards pile up when the same models are used at two locations (work + home G513 / MX Master 3S), and a just-plugged keyboard waits seconds for its configured lighting. Root causes: persisted known_identities resurrect unreachable devices as placeholders with model-key dedup defeated by the flaky extended-model byte (0b034 vs 2b034, #271/#280), and the inventory watcher is a pure 2 s poll — the "async-hid has no listener API" rationale predates async-hid 0.5's watch().

Demo

• Plug in a wired keyboard: configured lighting applies within ~1 s (hotplug wake + one confirming re-apply that absorbs the boot race).
• Unplug a Bolt receiver: its paired devices no longer linger as offline cards; a live MX Master 3S no longer renders next to a phantom same-model card.
• cargo test --workspace passes; clippy/fmt clean.

Changes

• Expose OS hotplug events from the shared backend: hotplug.rs, transport.rs (openlogi-hid)
• Wake the inventory watcher on hotplug events, keep the 2 s tick as reconciliation: watchers/inventory.rs
• Re-apply volatile settings once more after a first sighting: orchestrator.rs
• Suppress offline placeholders whose receiver is absent and dedup same-model cards by wire PID: state/devices.rs

Notes

• Verified on macOS (unit tests + hotplug stream smoke test); real plug/unplug hardware pass still pending — hence draft.
• Follow-up worth discussing: keying device identity on the HID++ 0x0003 serial/unit id with the route as an attribute, so one physical unit keeps one config entry across transports.

[greptile-apps]

Greptile Summary

This PR replaces the pure 2 s polling inventory watcher with a hotplug-driven design (using async-hid 0.5's watch()) and fixes two phantom-card regressions: stale offline placeholders for devices behind an absent receiver (#271/#280) and same-model duplicates caused by the flaky extended-model byte.

• inventory.rs: wakes early on OS hotplug events via tokio::select!; initialises the stream inside rt.block_on() so a Linux AsyncFd registration failure is a catchable Err rather than a panic; burst-drains with poll_once and degrades to polling if the stream closes.
• orchestrator.rs: introduces plan_reapply() and a reapply_followup set so first-sighted devices receive one confirming re-apply on the next tick, absorbing the device-boot race that can swallow the very first settings write.
• devices.rs: adds two gates in append_offline_known — a receiver-presence check (suppresses cards whose Bolt/Unifying receiver is unplugged) and a wire-PID dedup (collapses same-model records regardless of the extended-model byte).

Confidence Score: 5/5

Safe to merge; all three subsystems (hotplug watcher, first-sighting confirmation, phantom-card suppression) are guarded by dedicated unit tests and the changes degrade gracefully when hotplug is unavailable.

The hotplug stream initialisation is correctly placed inside rt.block_on(), fixing the thread-kill risk raised in the previous thread. The plan_reapply logic handles every edge case (offline during followup, wake + first sighting, replug under a new route) with matching test assertions. Receiver-absent filtering and wire-PID dedup in append_offline_known are symmetric in their lowercasing and correctly interact with the existing key-based dedup. No new unsafe code, no new IPC surface, no migrations.

No files require special attention; inventory.rs has the most surface area (new async select loop) but the fallback-to-polling path and stream-end detection are both tested or exercised by the existing WatchState tests.

Important Files Changed

Filename	Overview
crates/openlogi-hid/src/hotplug.rs	New file bridging async-hid's DeviceEvent stream to a typed HotplugEvent; maps both event variants and re-uses the shared HidBackend singleton.
crates/openlogi-hid/src/transport.rs	Adds pub(crate) hid_backend() accessor for the LazyLock singleton; minimal and correct.
crates/openlogi-agent-core/src/watchers/inventory.rs	Adds hotplug-driven early wakeup via tokio::select!, correctly initialising the hotplug stream inside rt.block_on() so an AsyncFd registration panic on Linux becomes a catchable Err; burst-drains with poll_once and falls back to polling when the stream closes.
crates/openlogi-agent-core/src/orchestrator.rs	Introduces plan_reapply() and a reapply_followup set to schedule one confirming re-apply for first-sighted devices, absorbing the device-boot race. Logic is sound: offline devices drop their followup entry; reapply_all only queues new devices for confirmation, not known ones.
crates/openlogi-gui/src/state/devices.rs	Adds two phantom-card suppression gates: receiver-absent filter using receiver_uid_of() with consistent lowercase normalisation, and wire-PID dedup via record_wire_pid(). Sort order ensures the richer record wins when two same-model keys exist.

_{Reviews (5): Last reviewed commit: "Merge branch 'master' into fix/device-li..." | Re-trigger Greptile}