v1.0.0

Make the live-tune (F1) hotkey rebindable from the dashboard

The settings-overlay hotkey was config-only; now it has the same
press-a-key rebind dialog as the tracking toggle. RebindHotkey takes
a `target` prop ("activate" | "settings") and routes to the matching
Rust command (rebind_hotkey / rebind_settings_hotkey, both already
present). Dashboard adds a "Change" button next to the live-tune
hotkey row in Advanced.

Kept at 1.0.0 — no version bump.