docs: sync Locator beeper docs with leave-mode change

The Beeper row is now hidden in Leave-only mode (homing only applies when
approaching a target), so drop the "works independently of arrive/leave"
wording and note the Arrive/Both-only availability.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/solo_features/tools_screen/tools_screen.md

@@ -263,13 +263,13 @@ Navigate with **UP/DOWN**, change a value with **LEFT/RIGHT** (or **Enter**); **
 | Target  | none / person / waypoint         | **Enter** opens a picker — **None** first (clears the target), then **favourites** (offered even with no known position yet, so you can arm ahead of time), then any other contact with a currently-resolvable position (live-sharing *or* just last-advertised, e.g. a repeater), then waypoints; **UP/DOWN** + **Enter** to choose. **LEFT/RIGHT** quick-cycles the same set in place, including back to **None**. A person is shown with an `@` prefix, plus a compact **age tag** (e.g. `@Bob (5m)`) when the position is last-advertised rather than a live share. Shows `none` until set. |
 | Radius  | 50 / 100 / 250 / 500 m / 1 km    | Geofence size.                                                                          |
 | Mode    | Arrive / Leave / Both            | Which crossing fires the alert — entering the radius, leaving it, or both.              |
-| Beeper  | ON / OFF                         | Optional homing tone (see below).                                                       |
+| Beeper  | ON / OFF                         | Optional homing tone — shown only in **Arrive** / **Both** modes (see below).           |
 
 **Crossing alert.** When armed with a target, the device watches its own GPS fix and fires the alert (a short melody plus an on-screen message) the moment you cross the radius, according to **Mode**. The wording adapts to the target — `Arrived` / `Left` for a waypoint, `Near` / `Away` for a person. The edge has a little hysteresis so a fix hovering right on the boundary doesn't chatter, and the first reading after arming only seeds the in/out state — it won't fire spuriously just because you armed it while already inside.
 
 **Following a person.** Pick a **favourite** (or any contact with a known position) as the target and the geofence tracks the distance *between you and them*, so it works even while both of you move. The position is resolved with a fixed precedence: an **active live `[LOC]` share** wins, and with no current share it **falls back to the contact's last-advertised GPS position** — so a rarely-updating but stationary node (a repeater, or someone who shared a fix once) still works as a target. You can arm it **ahead of time** — choosing a favourite locks onto their identity (pubkey), and the alert starts working as soon as a position is known. Live following requires a **DM** share (a channel share carries no stable identity to lock onto); the last-advertised fallback works for any contact regardless.
 
-**Proximity beeper.** With **Beeper** on, the device also ticks while you're inside the radius and **shortens the gap between ticks the closer you get to the target** — slow near the edge, rapid near the centre — like a homing beeper guiding you to the exact spot. It's silent outside the radius. Because the beeper is its own opt-in toggle, turning it on **overrides the global buzzer mute** (**Settings › Sound › Buzzer**) — it's an explicit "I want to hear this". It works independently of the arrive/leave crossing alert (which does follow the mute), so you can use either or both.
+**Proximity beeper.** With **Beeper** on, the device also ticks while you're inside the radius and **shortens the gap between ticks the closer you get to the target** — slow near the edge, rapid near the centre — like a homing beeper guiding you to the exact spot. It's silent outside the radius. Because the beeper is its own opt-in toggle, turning it on **overrides the global buzzer mute** (**Settings › Sound › Buzzer**) — it's an explicit "I want to hear this". Since homing only makes sense while you're approaching a target, the **Beeper** row appears only in **Arrive** or **Both** mode — it's hidden in **Leave**-only mode, and stays silent there even if it was switched on earlier. Otherwise it's independent of the crossing alert (which does follow the mute), so you can use either or both.
 
 **Setting the target from anywhere.** Besides this screen's picker, the *same* active target can be set in one step with **Set as target** from **Nearby Nodes**' or **Waypoints**' own **Hold Enter** menu — handy so you don't need a detour through Tools. Picking from this screen's picker saves on exit (so **LEFT/RIGHT** cycling stays cheap); the per-item shortcuts save immediately and confirm with a `Target set` toast.