docs(repeater): rename "politeness" -> "forwarding filters", fix stale refs

Rename the repeater filter knobs from "politeness" to "forwarding
filters" across code comments, FEATURES.md and the docs, and correct
references that hadn't followed the controls when they moved from
Settings › Radio to the dedicated Tools › Repeater screen.

Comment/doc accuracy fixes:
- NodePrefs: user_radio_presets are now written by both Settings and
  Repeater (shared picker), not Settings only.
- DiagnosticsScreen: class header listed only some rows; spell out the
  full set (forwarded, signal, pool/queue, error flags, reset gesture).
- RepeaterScreen header no longer claims to show live forwarding stats
  (they live on Diagnostics).
- tools_screen.md: drop the stale paragraph claiming the Repeater screen
  shows live stats at the bottom — it is config-only.

Comments/docs only; no behaviour change.

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

examples/companion_radio/MyMesh.cpp

@@ -283,7 +283,7 @@ int MyMesh::calcRxDelay(float score, uint32_t air_time) const {
 uint32_t MyMesh::getRetransmitDelay(const mesh::Packet *packet) {
   uint32_t t = (_radio->getEstAirtimeFor(packet->getPathByteLen() + packet->payload_len + 2) * 0.5f);
   uint32_t d = getRNG()->nextInt(0, 5*t + 1);
-  // Politeness yield (Settings > Radio): scale the flood retransmit delay so a
+  // Yield filter (Tools > Repeater): scale the flood retransmit delay so a
   // mobile companion waits longer and lets better-sited fixed repeaters win the
   // flood first. Only forwarded floods reach here — own sends pass their own
   // delay to sendFlood() — so this never slows the companion's own traffic.
@@ -556,7 +556,7 @@ bool MyMesh::isRepeatLooped(const mesh::Packet* packet) const {
 
 bool MyMesh::allowPacketForward(const mesh::Packet* packet) {
   if (_prefs.client_repeat == 0) return false;
-  // "Politeness" filters (Settings > Radio) — all default off, so a plain repeater
+  // Forwarding filters (Tools > Repeater) — all default off, so a plain repeater
   // is unaffected. Flood-only by design: on a direct route this node is the named
   // next hop, so dropping there would kill delivery with no alternate path, while
   // dropping a flood copy just trims redundancy other nodes still carry.
@@ -1848,7 +1848,7 @@ void MyMesh::handleCmdFrame(size_t len) {
     }
 
     // Dedicated-band requirement for app-driven repeat disabled, to match the
-    // on-device Repeater toggle (Settings > Radio), which repeats on whatever
+    // on-device Repeater toggle (Tools > Repeater), which repeats on whatever
     // frequency is already set with no band restriction. Uncomment to restore
     // the old behaviour (repeat=1 only accepted on repeat_freq_ranges, i.e.
     // 433.000/869.495/918.000 MHz exactly, by default).