refactor(companion): dedup age formatting + reply-prefix parsing; drop dead code

Consolidation pass over the message/nearby UI, no functional change beyond
one intentional display tweak:

- Age tags: NearbyScreen::fmtAge, the nearby list's inline column, and
  QuickMsgScreen::fmtMsgAge each reimplemented the same s/m/h bucket ladder
  on top of geo::fmtAgeShort. All now delegate to it (fmtMsgAge removed).
  Visible effect: ages over 24h render as "Nd" instead of capped hours,
  matching the Locator target picker which already used fmtAgeShort.
- Reply prefix: the "@[nick] " parse was duplicated in skipReplyPrefix() and
  FullscreenMsgView::render(). Extracted to one msgReplyBody() helper (body,
  plus optional addressee nick) — one place to handle its edge cases.
- LiveTrack: the expiry predicate was duplicated in expire()/isActive();
  extracted to a private expired() helper.
- Removed a dead M_PI define (and unused <math.h>) in NearbyScreen.h, and a
  comment pointing at a CODE_REVIEW.md that doesn't exist.

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

examples/companion_radio/LiveTrack.h

@@ -51,14 +51,9 @@ public:
   }
 
   // Drop entries not refreshed within EXPIRY_SECS. `now` is RTC epoch seconds.
-  // Guarded against now < ts (RTC stepped backwards) so a clock fix can't wipe
-  // the table.
   void expire(uint32_t now) {
-    for (int i = 0; i < CAPACITY; i++) {
-      if (_e[i].used && now > _e[i].ts && (now - _e[i].ts) > EXPIRY_SECS) {
-        _e[i].used = false;
-      }
-    }
+    for (int i = 0; i < CAPACITY; i++)
+      if (_e[i].used && expired(_e[i], now)) _e[i].used = false;
   }
 
   void clear() { for (int i = 0; i < CAPACITY; i++) _e[i].used = false; }
@@ -66,9 +61,7 @@ public:
   // Slot-wise access (caller skips inactive slots via isActive()).
   const Entry& slotAt(int i) const { return _e[i]; }
   bool isActive(int i, uint32_t now) const {
-    const Entry& e = _e[i];
-    if (!e.used) return false;
-    return !(now > e.ts && (now - e.ts) > EXPIRY_SECS);
+    return _e[i].used && !expired(_e[i], now);
   }
 
   // Number of currently non-expired entries.
@@ -94,6 +87,13 @@ public:
 private:
   Entry _e[CAPACITY] = {};
 
+  // An entry is stale once EXPIRY_SECS have passed since its last update.
+  // Guarded against now < ts (RTC stepped backwards) so a clock fix can't
+  // mass-expire the table.
+  static bool expired(const Entry& e, uint32_t now) {
+    return now > e.ts && (now - e.ts) > EXPIRY_SECS;
+  }
+
   // Match an existing entry: verified shares by key, channel shares by name.
   int find(const uint8_t* key, const char* name, bool verified) const {
     for (int i = 0; i < CAPACITY; i++) {

examples/companion_radio/ui-new/FullscreenMsgView.h

@@ -10,12 +10,35 @@ static const int FS_CHARS_MAX = 80;  // max bytes per wrapped line
 // fullscreen message view and the history list are never laid out in the same
 // frame (opening the fullscreen view early-returns before the list loop runs),
 // so one static buffer serves both. This keeps ~1.5 KB of line buffers off the
-// render-call stack (see CODE_REVIEW.md "Render-path stack peak") at the cost of
-// a fixed RAM allocation. Only used inside render()/wrap helpers — never across
-// a yield, so the single instance is safe.
+// render-call stack at the cost of a fixed RAM allocation. Only used inside
+// render()/wrap helpers — never across a yield, so the single instance is safe.
 static char s_wrap_trans[512];
 static char s_wrap_lines[12][FS_CHARS_MAX];
 
+// Parse a leading "@[nick] " reply prefix. Returns the message body that
+// follows it (and any leading whitespace); when nick/nick_n are supplied,
+// fills nick with the addressee, or "" when there's no prefix. One parser for
+// both the history list (body only — see QuickMsgScreen::skipReplyPrefix) and
+// the fullscreen view (which also shows the "To:" nick).
+static inline const char* msgReplyBody(const char* text, char* nick = nullptr, int nick_n = 0) {
+  if (nick && nick_n > 0) nick[0] = '\0';
+  const char* body = text;
+  if (text[0] == '@' && text[1] == '[') {
+    const char* close = strchr(text + 2, ']');
+    if (close && close[1] == ' ' && close[2]) {
+      if (nick && nick_n > 0) {
+        int len = (int)(close - text) - 2;
+        if (len > nick_n - 1) len = nick_n - 1;
+        memcpy(nick, text + 2, len);
+        nick[len] = '\0';
+      }
+      body = close + 2;
+    }
+  }
+  while (*body == '\n' || *body == '\r' || *body == ' ') body++;
+  return body;
+}
+
 struct FullscreenMsgView {
   int  scroll;
   bool active;
@@ -80,19 +103,9 @@ struct FullscreenMsgView {
     const int lineH  = display.getLineHeight();
     const int max_px = display.width() - 6;
 
-    // detect @recipient at start of message
-    char to_nick[32] = "";
-    const char* body = text;
-    if (text[0] == '@' && text[1] == '[') {
-      const char* close = strchr(text + 2, ']');
-      if (close && close[1] == ' ' && close[2]) {
-        int len = (int)(close - text) - 2;
-        if (len >= (int)sizeof(to_nick)) len = sizeof(to_nick) - 1;
-        memcpy(to_nick, text + 2, len);
-        to_nick[len] = '\0';
-        body = close + 2;
-      }
-    }
+    // "@[nick] " reply prefix → "To:" header + body (shared parser).
+    char to_nick[32];
+    const char* body = msgReplyBody(text, to_nick, sizeof(to_nick));
 
     const int cw       = display.getCharWidth();
     const int header_h = to_nick[0] ? (lineH * 2 + 4) : (lineH + 2);

examples/companion_radio/ui-new/NearbyScreen.h

@@ -1,12 +1,7 @@
 #pragma once
-#include <math.h>
 #include "../GeoUtils.h"
 #include "NavView.h"
 
-#ifndef M_PI
-  #define M_PI 3.14159265358979323846
-#endif
-
 // ── Nearby Nodes ──────────────────────────────────────────────────────────────
 // One list / detail / action-menu interaction path over two sources:
 //   SRC_STORED — contacts known to the mesh (distance / bearing / last-heard)
@@ -111,14 +106,13 @@ class NearbyScreen : public UIScreen {
 
   bool useImperial() const { return _task && _task->useImperial(); }
 
+  // Full "X ago" form for the detail view, built on the shared short-age tag
+  // so there's one bucket ladder (see geo::fmtAgeShort).
   static void fmtAge(char* buf, int n, uint32_t lastmod) {
-    uint32_t now = rtc_clock.getCurrentTime();
-    if (now < lastmod || lastmod == 0) { snprintf(buf, n, "unknown"); return; }
-    uint32_t age = now - lastmod;
-    if      (age < 60)     snprintf(buf, n, "%us ago",  age);
-    else if (age < 3600)   snprintf(buf, n, "%um ago",  age / 60);
-    else if (age < 86400)  snprintf(buf, n, "%uh ago",  age / 3600);
-    else                   snprintf(buf, n, ">1d ago");
+    char s[8];
+    geo::fmtAgeShort(s, sizeof(s), rtc_clock.getCurrentTime(), lastmod);
+    if (!s[0]) { snprintf(buf, n, "unknown"); return; }
+    snprintf(buf, n, "%s ago", s);
   }
 
   static const char* typeName(uint8_t t) {
@@ -715,14 +709,8 @@ public:
         if (_source == SRC_SCAN) {
           snprintf(right, sizeof(right), "%d", (int)e.rssi);
         } else if (_sort == SORT_TIME) {
-          uint32_t now = rtc_clock.getCurrentTime();
-          if (e.lastmod == 0 || now < e.lastmod)  snprintf(right, sizeof(right), "?");
-          else {
-            uint32_t age = now - e.lastmod;
-            if      (age < 60)   snprintf(right, sizeof(right), "%us", age);
-            else if (age < 3600) snprintf(right, sizeof(right), "%um", age / 60);
-            else                 snprintf(right, sizeof(right), "%uh", age / 3600);
-          }
+          geo::fmtAgeShort(right, sizeof(right), rtc_clock.getCurrentTime(), e.lastmod);
+          if (!right[0]) snprintf(right, sizeof(right), "?");   // unknown / RTC not synced
         } else {
           if (e.dist_km >= 0.0f) geo::fmtDist(right, sizeof(right), e.dist_km, useImperial());
           else                   strncpy(right, "?GPS", sizeof(right));

examples/companion_radio/ui-new/QuickMsgScreen.h

@@ -209,15 +209,9 @@ class QuickMsgScreen : public UIScreen {
     return r;
   }
 
-  // Strip "@[nick] " reply prefix from a message body for compact list display.
-  static const char* skipReplyPrefix(const char* text) {
-    if (text[0] == '@' && text[1] == '[') {
-      const char* close = strchr(text + 2, ']');
-      if (close && close[1] == ' ' && close[2]) text = close + 2;
-    }
-    while (*text == '\n' || *text == '\r' || *text == ' ') text++;
-    return text;
-  }
+  // Strip the "@[nick] " reply prefix for compact list display (body only).
+  // Shares the one parser with the fullscreen view — see msgReplyBody().
+  static const char* skipReplyPrefix(const char* text) { return msgReplyBody(text); }
 
   // Split a DM-history entry into the name to show as the author and the body to
   // show beneath it. Room servers carry many guests, so incoming room posts are
@@ -351,15 +345,6 @@ class QuickMsgScreen : public UIScreen {
   }
 
 
-  static void fmtMsgAge(char* buf, int n, uint32_t timestamp, uint32_t now) {
-    if (timestamp == 0 || now < timestamp) { buf[0] = '\0'; return; }
-    uint32_t age = now - timestamp;
-    if      (age < 60)    snprintf(buf, n, "%us", age);
-    else if (age < 3600)  snprintf(buf, n, "%um", age / 60);
-    else if (age < 86400) snprintf(buf, n, "%uh", age / 3600);
-    else                  snprintf(buf, n, ">1d");
-  }
-
   // count history entries for a specific channel
   int histCountForChannel(int ch_idx) const {
     int n = 0;
@@ -1207,7 +1192,7 @@ public:
         const char* body = dmDisplayParts(e, is_room, filtered_name, sender_buf, sizeof(sender_buf));
         const char* sender = sender_buf;
 
-        char age[6]; fmtMsgAge(age, sizeof(age), e.timestamp, now_ts);
+        char age[6]; geo::fmtAgeShort(age, sizeof(age), now_ts, e.timestamp);
         int age_w = age[0] ? display.getTextWidth(age) + 3 : 0;
 
         if (sel) {
@@ -1368,7 +1353,7 @@ public:
           msg_part[sizeof(msg_part) - 1] = '\0';
         }
 
-        char age[6]; fmtMsgAge(age, sizeof(age), _hist[ring_pos].timestamp, now_ts);
+        char age[6]; geo::fmtAgeShort(age, sizeof(age), now_ts, _hist[ring_pos].timestamp);
         int age_w = age[0] ? display.getTextWidth(age) + 3 : 0;
 
         if (sel) {