feat(repeater): politeness controls, dedicated radio profile, and diagnostics

Settings > Radio gains a repeater toggle, 16 community-suggested radio
presets plus manual Freq/SF/BW/CR tuning (digit-by-digit Freq editor),
4 persisted user preset slots, and the packet pool bumped 16->32 so
queued retransmits stop starving incoming-packet allocation while
relaying.

Four opt-in politeness knobs (skip-advert, max-hops, yield, min-SNR),
all flood-only and off by default, plus overhear suppression that
cancels a queued retransmit if a peer relays the same packet first.
Adaptive Power Control is suppressed while relaying (pins TX power to
the ceiling) and duty-cycle RX is forced off, since a repeater needs
to hear and relay at consistent power.

A dedicated Tools > Repeater screen consolidates the toggle, the
politeness knobs, and live forwarding stats, plus an optional "Custom"
radio profile — a dedicated frequency/SF/BW/CR for relaying, separate
from the companion's own network, band-matched to the companion
frequency by default and used everywhere a radio change can happen
(boot, on-device toggle, app-driven CMD_SET_RADIO_PARAMS, Settings
radio edits) so the device never silently falls back to the wrong
params mid-relay.

Diagnostics gains the actually-forwarded packet count, real heap-free
via mallinfo(), a reset-counters popup, and hardened loop-detect
bounds. Also: a frequency-floor fix and a float-equality preset-match
fix in the repeater profile logic, deduped BW-table/valCol/profile-
seeding helpers shared between Settings and the Repeater screen, and
a build.sh fix tolerating control characters in `pio project config`'s
JSON dump.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/solo_features/settings_screen/settings_screen.md

@@ -65,9 +65,16 @@ Lists all available home screen pages. For each entry:
 
 | Setting   | Options    | Notes                                                                                                                                                              |
 | --------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
-| TX power  | 2–22 dBm   | LEFT/RIGHT. With **Auto pwr** on this is the *ceiling* — the radio may transmit lower. |
-| Pwr save  | ON / OFF   | **Battery saver.** Hardware duty-cycle receive: the SX126x cycles RX↔sleep on its own and wakes on a preamble, cutting average RX current. Trades a little receive latency; leave OFF for lowest-latency reception. Requires an SX126x radio (otherwise stays on continuous RX). |
-| Auto pwr  | ON / OFF   | **Adaptive Power Control.** Lowers actual TX power on strong links to save energy, ramping back up — to the **TX power** ceiling — on weak or lost links. Link quality comes from direct-message ACK SNR and, for channel messages (no ACK), from hearing a repeater rebroadcast your packet. The radio page / name bar shows the live power. Default OFF (fixed TX power). |
+| TX Pwr    | 2–22 dBm   | LEFT/RIGHT. With **Auto pwr** on this is the *ceiling* — the radio may transmit lower. |
+| Preset    | named presets | LEFT/RIGHT cycles community RF presets (region frequency + bandwidth/SF/CR). **Enter** opens a popup to pick one, save the current settings as a named preset, or delete a saved one. Applies frequency, bandwidth, SF and CR together. |
+| Freq      | chip range | **Enter** opens a digit-by-digit editor: LEFT/RIGHT moves between decimal places, UP/DOWN steps that digit. Bounds come from the radio chip's own validated range, so a value the radio would reject can't be entered. |
+| SF        | 5–12       | LEFT/RIGHT. Spreading factor. |
+| BW        | 7.8–500 kHz | LEFT/RIGHT cycles the standard LoRa bandwidths. |
+| CR        | 5–8        | LEFT/RIGHT. Coding rate (4/5–4/8). |
+| Pwr save  | ON / OFF   | **Battery saver.** Hardware duty-cycle receive: the SX126x cycles RX↔sleep on its own and wakes on a preamble, cutting average RX current. Trades a little receive latency; leave OFF for lowest-latency reception. Requires an SX126x radio (otherwise stays on continuous RX). **Forced off (shown as `--`) while the repeater is on** — a repeater must listen continuously; your setting is restored when the repeater is switched off. |
+| Auto pwr  | ON / OFF   | **Adaptive Power Control.** Lowers actual TX power on strong links to save energy, ramping back up — to the **TX Pwr** ceiling — on weak or lost links. Link quality comes from direct-message ACK SNR and, for channel messages (no ACK), from hearing a repeater rebroadcast your packet. The radio page / name bar shows the live power. Default OFF (fixed TX power). **Suppressed (shown as `--`) while the repeater is on** — a repeater holds full TX power for consistent relay reach; your setting is restored when the repeater is switched off. |
+
+The **repeater** mode and its flood filters live on their own screen — see **Tools › Repeater**.
 
 ---