refactor(companion): extract MessageHistory store from QuickMsgScreen

Move the two RAM history rings (channel + DM) out of the 1988-line
QuickMsgScreen into a self-contained MessageHistory.h component, mirroring
the WaypointsView extraction from TrailScreen. The store owns the ring
buffers, per-entry delivery state (channel relay echo, DM end-to-end ACK +
auto-resend) and the per-channel unread counters; the screen keeps all
view state (selection, scroll, fullscreen readers, the unread "viewing
session" bookkeeping) and reaches entries through accessors.

Behaviour-preserving:
- The shared types (AckState, ChHistEntry, DmHistEntry, MSG_TEXT_BUF) are
  file-scope in MessageHistory.h, so the phase machine still refers to them
  unqualified — only data + storage logic moved.
- addChannelMsg keeps a thin screen forwarder that computes the "viewing"
  flag (a phase fact the store can't see) and returns the ring pos;
  afterSend uses armChannelRelay(pos, seq) instead of poking the ring.
- The public API called via UITask/MyMesh/the bot (addChannelMsg, addDMMsg,
  markDmDelivered, markChannelRelayed, tickDmResends, clearAllChannelUnread,
  getTotalChannelUnread, getRecentDMContacts) stays on QuickMsgScreen as
  forwarders, so no caller changes.

QuickMsgScreen 1988 -> 1738 lines; MessageHistory.h 324. Both solo boards
build. Single-TU fragment: included by UITask.cpp before QuickMsgScreen.h.

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

examples/companion_radio/ui-new/MessageHistory.h

@@ -0,0 +1,324 @@
+#pragma once
+// Message history store for QuickMsgScreen: two RAM ring buffers (channel + DM)
+// with their per-entry delivery state (channel "relayed into mesh" echo, DM
+// end-to-end ACK + auto-resend) and the per-channel unread counters. Pure
+// storage + queries — no UI/phase state lives here. The screen keeps selection,
+// scroll, the unread "viewing session" bookkeeping, the room-login table, and
+// all rendering, and reaches entries through the accessors below.
+//
+// Single-TU fragment: included by UITask.cpp before QuickMsgScreen.h. AckState,
+// MSG_TEXT_BUF and the two entry structs are file-scope (not nested) so the
+// phase machine in QuickMsgScreen keeps referring to them unqualified.
+
+// Outgoing-message delivery state. DM: a real end-to-end ACK (✓ delivered to
+// the recipient). Channel: only a "relayed into mesh" echo from a repeater (no
+// recipient ACK exists for floods), so a missing echo is NOT shown as failure.
+enum AckState : uint8_t { ACK_NONE = 0, ACK_PENDING, ACK_OK, ACK_FAIL };
+
+// History text holds a full received message. Channel messages carry the sender
+// embedded as "Name: body" in the payload, so a message can be up to the
+// over-the-air maximum (MAX_TEXT_LEN). Size the buffers to that + NUL, otherwise
+// long messages (and Polish text, where each accented char is two UTF-8 bytes)
+// get their tail clipped.
+static const int MSG_TEXT_BUF = MAX_TEXT_LEN + 1;
+
+struct ChHistEntry {
+  uint8_t  ch_idx;
+  char     text[MSG_TEXT_BUF];
+  uint32_t timestamp;
+  uint8_t  relay_status;   // AckState; only PENDING/OK used (no failure for floods)
+  uint32_t relay_seq;      // MyMesh relay seq to match against onChannelRelayed()
+};
+
+struct DmHistEntry {
+  uint8_t  prefix[4];
+  uint8_t  outgoing;
+  char     text[MSG_TEXT_BUF];
+  uint32_t timestamp;
+  uint8_t  ack_status;       // AckState; meaningful only when outgoing
+  uint32_t ack_tag;          // expected_ack CRC to match against onMsgAck()
+  uint32_t ack_deadline_ms;  // millis() by which a pending ACK must arrive
+  // Sender-perspective message timestamp: the send timestamp for outgoing
+  // (reused verbatim on resend so the recipient treats it as a retry), or the
+  // sender_timestamp for incoming (used to dedup retried copies). 0 = unknown.
+  uint32_t msg_ts;
+  uint8_t  attempt;          // last attempt number sent (outgoing); next resend = attempt+1
+  uint8_t  resends_left;     // remaining auto-resends before the marker shows ✗
+};
+
+class MessageHistory {
+public:
+  // Shared ring for all channels combined; each slot carries a full MSG_TEXT_BUF,
+  // so this ring dominates RAM — kept modest to leave heap headroom (see
+  // DM_HIST_MAX). The DM ring is likewise bounded.
+  static const int CH_HIST_MAX = 48;
+  static const int DM_HIST_MAX = 32;
+
+  MessageHistory()
+    : _hist_head(0), _hist_count(0), _dm_hist_head(0), _dm_hist_count(0) {
+    memset(_ch_unread, 0, sizeof(_ch_unread));
+  }
+
+  // ── Channel ring ──────────────────────────────────────────────────────────
+
+  // Append a channel message. `viewing` = the user is currently in this
+  // channel's history (so it isn't counted unread). `timestamp` is the sender's
+  // own send time (0 = unknown — use receipt time). Returns the ring position
+  // (an opaque handle for armChannelRelay / chAtPos), or -1 if rejected.
+  int addChannelMsg(uint8_t ch_idx, const char* text, bool viewing, uint32_t timestamp = 0) {
+    // Guard against bogus channel indices (e.g. findChannelIdx() returned -1
+    // and was cast to uint8_t → 255). Storing such an entry would burn a ring
+    // slot for a message that no visible channel can ever surface.
+    if (ch_idx >= MAX_GROUP_CHANNELS) return -1;
+    int pos;
+    if (_hist_count < CH_HIST_MAX) {
+      pos = (_hist_head + _hist_count) % CH_HIST_MAX;
+      _hist_count++;
+    } else {
+      pos = _hist_head;
+      // Evicting the oldest entry — drop its share of the unread counter so
+      // the badge can't claim a message the ring no longer holds.
+      uint8_t evicted = _hist[pos].ch_idx;
+      if (evicted < MAX_GROUP_CHANNELS && _ch_unread[evicted] > 0) {
+        _ch_unread[evicted]--;
+      }
+      _hist_head = (_hist_head + 1) % CH_HIST_MAX;
+    }
+    _hist[pos].ch_idx = ch_idx;
+    _hist[pos].timestamp = timestamp ? timestamp : rtc_clock.getCurrentTime();
+    strncpy(_hist[pos].text, text, sizeof(_hist[pos].text) - 1);
+    _hist[pos].text[sizeof(_hist[pos].text) - 1] = '\0';
+    _hist[pos].relay_status = ACK_NONE;
+    _hist[pos].relay_seq = 0;
+
+    if (!viewing && _ch_unread[ch_idx] < 99) _ch_unread[ch_idx]++;
+    return pos;
+  }
+
+  // count history entries for a specific channel
+  int histCountForChannel(int ch_idx) const {
+    int n = 0;
+    for (int i = 0; i < _hist_count; i++) {
+      if (_hist[(_hist_head + i) % CH_HIST_MAX].ch_idx == (uint8_t)ch_idx) n++;
+    }
+    return n;
+  }
+
+  // get ring-buffer position of j-th history entry for channel (newest first)
+  int histEntryForChannel(int ch_idx, int j) const {
+    int n = 0;
+    for (int i = _hist_count - 1; i >= 0; i--) {
+      int pos = (_hist_head + i) % CH_HIST_MAX;
+      if (_hist[pos].ch_idx == (uint8_t)ch_idx) {
+        if (n == j) return pos;
+        n++;
+      }
+    }
+    return -1;
+  }
+
+  // Called when a repeater echo of one of our channel sends is heard.
+  void markChannelRelayed(uint32_t seq) {
+    if (seq == 0) return;
+    for (int i = 0; i < _hist_count; i++) {
+      ChHistEntry& e = _hist[(_hist_head + i) % CH_HIST_MAX];
+      if (e.relay_status == ACK_PENDING && e.relay_seq == seq) {
+        e.relay_status = ACK_OK;
+        return;
+      }
+    }
+  }
+
+  // Arm the "relayed into mesh" marker on a just-sent entry (pos from
+  // addChannelMsg) — MyMesh tracked the flood it originated and will report a
+  // heard repeater echo by seq.
+  void armChannelRelay(int pos, uint32_t seq) {
+    if (pos < 0 || pos >= CH_HIST_MAX) return;
+    _hist[pos].relay_status = ACK_PENDING;
+    _hist[pos].relay_seq    = seq;
+  }
+
+  ChHistEntry&       chAtPos(int pos)       { return _hist[pos]; }
+  const ChHistEntry& chAtPos(int pos) const { return _hist[pos]; }
+
+  // ── Per-channel unread counters ─────────────────────────────────────────────
+  uint8_t chUnread(int ch) const {
+    return (ch >= 0 && ch < MAX_GROUP_CHANNELS) ? _ch_unread[ch] : 0;
+  }
+  void setChUnread(int ch, uint8_t v) {
+    if (ch >= 0 && ch < MAX_GROUP_CHANNELS) _ch_unread[ch] = v;
+  }
+  void clearAllChannelUnread() { memset(_ch_unread, 0, sizeof(_ch_unread)); }
+  int  getTotalChannelUnread() const {
+    int total = 0;
+    for (int i = 0; i < MAX_GROUP_CHANNELS; i++) total += _ch_unread[i];
+    return total;
+  }
+
+  // ── DM ring ─────────────────────────────────────────────────────────────────
+
+  // ack_tag != 0 marks an outgoing DM as awaiting an end-to-end ACK by
+  // ack_deadline_ms; 0 means "sent, no confirmation possible" (no path / incoming).
+  // msg_ts = sender-perspective timestamp (send ts for outgoing / sender_timestamp
+  // for incoming); resends = remaining auto-resends for an outgoing pending DM.
+  void storeDMMsg(const uint8_t* pub_key, bool outgoing, const char* text,
+                  uint32_t ack_tag = 0, uint32_t ack_deadline_ms = 0,
+                  uint32_t msg_ts = 0, uint8_t resends = 0) {
+    int pos;
+    if (_dm_hist_count < DM_HIST_MAX) {
+      pos = (_dm_hist_head + _dm_hist_count) % DM_HIST_MAX;
+      _dm_hist_count++;
+    } else {
+      pos = _dm_hist_head;
+      _dm_hist_head = (_dm_hist_head + 1) % DM_HIST_MAX;
+    }
+    memcpy(_dm_hist[pos].prefix, pub_key, 4);
+    _dm_hist[pos].outgoing = outgoing ? 1 : 0;
+    // Prefer the sender's own timestamp — a room-sync replay or an
+    // offline-queued message held by a repeater can arrive long after it was
+    // actually sent, so "now" would mislabel every backlog message as fresh.
+    // Fall back to receipt time only when the sender's timestamp is unknown.
+    _dm_hist[pos].timestamp = msg_ts ? msg_ts : rtc_clock.getCurrentTime();
+    strncpy(_dm_hist[pos].text, text, sizeof(DmHistEntry::text) - 1);
+    _dm_hist[pos].text[sizeof(DmHistEntry::text) - 1] = '\0';
+    _dm_hist[pos].ack_status      = (outgoing && ack_tag) ? ACK_PENDING : ACK_NONE;
+    _dm_hist[pos].ack_tag         = ack_tag;
+    _dm_hist[pos].ack_deadline_ms = ack_deadline_ms;
+    _dm_hist[pos].msg_ts          = msg_ts;
+    _dm_hist[pos].attempt         = 0;
+    _dm_hist[pos].resends_left    = (outgoing && ack_tag) ? resends : 0;
+  }
+
+  void addDMMsg(const uint8_t* pub_key, bool outgoing, const char* text,
+                uint32_t sender_timestamp = 0) {
+    // Drop retried copies of an incoming DM: a resend reuses the sender's
+    // timestamp and text but carries a fresh packet hash, so the mesh dup-filter
+    // lets it through. Match on prefix + sender_timestamp + text to suppress it.
+    if (!outgoing && sender_timestamp != 0) {
+      for (int i = 0; i < _dm_hist_count; i++) {
+        const DmHistEntry& e = _dm_hist[(_dm_hist_head + i) % DM_HIST_MAX];
+        if (!e.outgoing && e.msg_ts == sender_timestamp &&
+            memcmp(e.prefix, pub_key, 4) == 0 && strcmp(e.text, text) == 0)
+          return;  // duplicate retry — already in history
+      }
+    }
+    storeDMMsg(pub_key, outgoing, text, 0, 0, outgoing ? 0 : sender_timestamp, 0);
+  }
+
+  int dmHistCountForContact(const uint8_t* prefix) const {
+    int n = 0;
+    for (int i = 0; i < _dm_hist_count; i++)
+      if (memcmp(_dm_hist[(_dm_hist_head + i) % DM_HIST_MAX].prefix, prefix, 4) == 0) n++;
+    return n;
+  }
+
+  int dmHistEntryForContact(const uint8_t* prefix, int j) const { // j=0 = newest
+    int n = 0;
+    for (int i = _dm_hist_count - 1; i >= 0; i--) {
+      int pos = (_dm_hist_head + i) % DM_HIST_MAX;
+      if (memcmp(_dm_hist[pos].prefix, prefix, 4) == 0) {
+        if (n == j) return pos;
+        n++;
+      }
+    }
+    return -1;
+  }
+
+  // Effective status for display. A pending ACK only reads as failed once its
+  // deadline has passed AND no auto-resends remain — while resends_left > 0 the
+  // entry stays pending (tickDmResends() retries / finalises it). Safety net for
+  // when the tick hasn't run yet; the tick is the authority that writes ACK_FAIL.
+  AckState dmEffectiveStatus(const DmHistEntry& e) const {
+    if (e.ack_status == ACK_PENDING && e.resends_left == 0 &&
+        (int32_t)(millis() - e.ack_deadline_ms) >= 0)
+      return ACK_FAIL;
+    return (AckState)e.ack_status;
+  }
+
+  // Called when an end-to-end ACK arrives (routed from MyMesh::onAckRecv).
+  // Marks the matching pending outgoing DM as delivered.
+  void markDmDelivered(uint32_t ack_crc) {
+    if (ack_crc == 0) return;
+    for (int i = 0; i < _dm_hist_count; i++) {
+      DmHistEntry& e = _dm_hist[(_dm_hist_head + i) % DM_HIST_MAX];
+      if (e.outgoing && e.ack_status == ACK_PENDING && e.ack_tag == ack_crc) {
+        e.ack_status = ACK_OK;
+        return;
+      }
+    }
+  }
+
+  // Periodic resend driver for outgoing DMs whose ACK deadline lapsed with no
+  // ACK: resend with the next attempt# (reusing the original timestamp so the
+  // recipient dedups) while resends remain, else mark it failed (✗).
+  void tickDmResends() {
+    uint32_t now = millis();
+    for (int i = 0; i < _dm_hist_count; i++) {
+      DmHistEntry& e = _dm_hist[(_dm_hist_head + i) % DM_HIST_MAX];
+      if (!e.outgoing || e.ack_status != ACK_PENDING) continue;
+      if ((int32_t)(now - e.ack_deadline_ms) < 0) continue;   // still waiting
+      if (e.resends_left == 0) { e.ack_status = ACK_FAIL; continue; }
+      ContactInfo c;
+      if (!contactByPrefix(e.prefix, c)) { e.ack_status = ACK_FAIL; continue; }
+      uint32_t expected_ack = 0, est_timeout = 0;
+      uint8_t next_attempt = e.attempt + 1;
+      if (the_mesh.sendMessage(c, e.msg_ts, next_attempt, e.text,
+                               expected_ack, est_timeout) > 0 && expected_ack) {
+        e.attempt         = next_attempt;
+        e.ack_tag         = expected_ack;   // each attempt has a distinct ACK CRC
+        e.ack_deadline_ms = now + est_timeout + 4000;
+        e.resends_left--;
+      } else {
+        e.ack_status = ACK_FAIL;            // couldn't compose/send — give up
+      }
+    }
+  }
+
+  // Recent DM contacts, newest first, deduped. Resolves the 4-byte _dm_hist
+  // prefix to a 6-byte pub_key prefix by walking the contact list once per
+  // unique sender. Returns the number filled.
+  int getRecentDMContacts(uint8_t out[][NodePrefs::FAVOURITE_PREFIX_LEN], int max) const {
+    int n = 0;
+    for (int i = _dm_hist_count - 1; i >= 0 && n < max; i--) {
+      int pos = (_dm_hist_head + i) % DM_HIST_MAX;
+      const uint8_t* p4 = _dm_hist[pos].prefix;
+      // Skip if already collected.
+      bool dup = false;
+      for (int j = 0; j < n; j++) if (memcmp(out[j], p4, 4) == 0) { dup = true; break; }
+      if (dup) continue;
+      // Find a real contact whose pub_key starts with this 4-byte prefix.
+      for (int idx = 0; ; idx++) {
+        ContactInfo c;
+        if (!the_mesh.getContactByIdx(idx, c)) break;
+        if (memcmp(c.id.pub_key, p4, 4) == 0) {
+          memcpy(out[n], c.id.pub_key, NodePrefs::FAVOURITE_PREFIX_LEN);
+          n++;
+          break;
+        }
+      }
+    }
+    return n;
+  }
+
+  DmHistEntry&       dmAtPos(int pos)       { return _dm_hist[pos]; }
+  const DmHistEntry& dmAtPos(int pos) const { return _dm_hist[pos]; }
+
+private:
+  // Look up a contact by 4-byte pub_key prefix (as stored in DmHistEntry).
+  bool contactByPrefix(const uint8_t* prefix, ContactInfo& out) const {
+    int total = the_mesh.getNumContacts();
+    for (int i = 0; i < total; i++) {
+      ContactInfo c;
+      if (!the_mesh.getContactByIdx(i, c)) continue;
+      if (memcmp(c.id.pub_key, prefix, 4) == 0) { out = c; return true; }
+    }
+    return false;
+  }
+
+  ChHistEntry _hist[CH_HIST_MAX];
+  int _hist_head, _hist_count;
+  uint8_t _ch_unread[MAX_GROUP_CHANNELS];
+
+  DmHistEntry _dm_hist[DM_HIST_MAX];
+  int _dm_hist_head, _dm_hist_count;
+};

examples/companion_radio/ui-new/QuickMsgScreen.h

@@ -26,7 +26,6 @@ class QuickMsgScreen : public UIScreen {
   int _channel_sel, _channel_scroll;
   int _num_channels;
   uint8_t _channel_indices[MAX_GROUP_CHANNELS];
-  uint8_t _ch_unread[MAX_GROUP_CHANNELS];
   int _sel_channel_idx;
   bool _sending_to_channel;
 
@@ -41,17 +40,12 @@ class QuickMsgScreen : public UIScreen {
   int _active_msgs[QUICK_MSGS_MAX];
   int _active_msg_count;
 
-  // CHANNEL_HIST
+  // CHANNEL_HIST — selection + the unread "viewing session" bookkeeping. The
+  // history ring itself and the per-channel unread counters live in _history.
   int _hist_sel, _hist_scroll;
   FullscreenMsgView _fs;
-  int  _unread_at_entry;    // _ch_unread value when entering CHANNEL_HIST
+  int  _unread_at_entry;    // channel unread count when entering CHANNEL_HIST
   int  _viewing_max_seen;  // highest _hist_sel reached in current session
-  // Shared ring for all channels combined. addChannelMsg() decrements the
-  // matching _ch_unread when an entry is evicted so the badge can't claim
-  // unread messages that no longer exist in the ring. Each slot carries a full
-  // MSG_TEXT_BUF, so this ring dominates the screen's RAM footprint — kept
-  // modest to leave heap headroom (see DM_HIST_MAX).
-  static const int CH_HIST_MAX = 48;
 
   // KEYBOARD
   KeyboardWidget* _kb;
@@ -90,48 +84,15 @@ class QuickMsgScreen : public UIScreen {
   // auto-share target (channel / DM) instead of composing a message.
   bool      _pick_target = false;
 
-  // History text holds a full received message. Channel messages carry the
+  // The message-history rings (channel + DM), their per-entry delivery state and
-  // sender embedded as "Name: body" in the payload, so a message can be up to
+  // per-channel unread counters live in this store (see MessageHistory.h). The
-  // the over-the-air maximum (MAX_TEXT_LEN). Size the buffers to that + NUL,
+  // phase machine below keeps only the view state — selection, scroll, the
-  // otherwise long messages (and Polish text, where each accented char is two
+  // fullscreen readers — and reaches entries through _history's accessors. The
-  // UTF-8 bytes) get their tail clipped.
+  // shared types (AckState, ChHistEntry, DmHistEntry, MSG_TEXT_BUF) are file-
-  static const int MSG_TEXT_BUF = MAX_TEXT_LEN + 1;
+  // scope, so they're still referred to unqualified throughout this screen.
+  MessageHistory _history;
 
-  // Outgoing-message delivery state. DM: a real end-to-end ACK (✓ delivered to
+  // DM_HIST view state (the ring itself is in _history).
-  // the recipient). Channel: only a "relayed into mesh" echo from a repeater (no
-  // recipient ACK exists for floods), so a missing echo is NOT shown as failure.
-  enum AckState : uint8_t { ACK_NONE = 0, ACK_PENDING, ACK_OK, ACK_FAIL };
-
-  struct ChHistEntry {
-    uint8_t  ch_idx;
-    char     text[MSG_TEXT_BUF];
-    uint32_t timestamp;
-    uint8_t  relay_status;   // AckState; only PENDING/OK used (no failure for floods)
-    uint32_t relay_seq;      // MyMesh relay seq to match against onChannelRelayed()
-  };
-  ChHistEntry _hist[CH_HIST_MAX];
-  int _hist_head, _hist_count;
-
-  // DM_HIST
-  struct DmHistEntry {
-    uint8_t  prefix[4];
-    uint8_t  outgoing;
-    char     text[MSG_TEXT_BUF];
-    uint32_t timestamp;
-    uint8_t  ack_status;       // AckState; meaningful only when outgoing
-    uint32_t ack_tag;          // expected_ack CRC to match against onMsgAck()
-    uint32_t ack_deadline_ms;  // millis() by which a pending ACK must arrive
-    // Sender-perspective message timestamp: the send timestamp for outgoing
-    // (reused verbatim on resend so the recipient treats it as a retry), or the
-    // sender_timestamp for incoming (used to dedup retried copies). 0 = unknown.
-    uint32_t msg_ts;
-    uint8_t  attempt;          // last attempt number sent (outgoing); next resend = attempt+1
-    uint8_t  resends_left;     // remaining auto-resends before the marker shows ✗
-  };
-  // Each slot carries a full MSG_TEXT_BUF; kept modest to bound heap use.
-  static const int DM_HIST_MAX = 32;
-  DmHistEntry _dm_hist[DM_HIST_MAX];
-  int _dm_hist_head, _dm_hist_count;
   int _dm_hist_sel, _dm_hist_scroll;
   FullscreenMsgView _dm_fs;
 
@@ -344,29 +305,6 @@ class QuickMsgScreen : public UIScreen {
     }
   }
 
-
-  // count history entries for a specific channel
-  int histCountForChannel(int ch_idx) const {
-    int n = 0;
-    for (int i = 0; i < _hist_count; i++) {
-      if (_hist[(_hist_head + i) % CH_HIST_MAX].ch_idx == (uint8_t)ch_idx) n++;
-    }
-    return n;
-  }
-
-  // get ring-buffer position of j-th history entry for channel (newest first)
-  int histEntryForChannel(int ch_idx, int j) const {
-    int n = 0;
-    for (int i = _hist_count - 1; i >= 0; i--) {
-      int pos = (_hist_head + i) % CH_HIST_MAX;
-      if (_hist[pos].ch_idx == (uint8_t)ch_idx) {
-        if (n == j) return pos;
-        n++;
-      }
-    }
-    return -1;
-  }
-
   // Delivery marker, drawn with the current ink colour and auto-scaled to the
   // font (see icons.h). Pending = a row of dots, one per send (so it grows with
   // each auto-resend); delivered = ✓; failed = ✗; ACK_NONE = nothing.
@@ -379,68 +317,6 @@ class QuickMsgScreen : public UIScreen {
     }
   }
 
-  // ack_tag != 0 marks an outgoing DM as awaiting an end-to-end ACK by
-  // ack_deadline_ms; 0 means "sent, no confirmation possible" (no path / incoming).
-  // msg_ts = sender-perspective timestamp (send ts for outgoing / sender_timestamp
-  // for incoming); resends = remaining auto-resends for an outgoing pending DM.
-  void storeDMMsg(const uint8_t* pub_key, bool outgoing, const char* text,
-                  uint32_t ack_tag = 0, uint32_t ack_deadline_ms = 0,
-                  uint32_t msg_ts = 0, uint8_t resends = 0) {
-    int pos;
-    if (_dm_hist_count < DM_HIST_MAX) {
-      pos = (_dm_hist_head + _dm_hist_count) % DM_HIST_MAX;
-      _dm_hist_count++;
-    } else {
-      pos = _dm_hist_head;
-      _dm_hist_head = (_dm_hist_head + 1) % DM_HIST_MAX;
-    }
-    memcpy(_dm_hist[pos].prefix, pub_key, 4);
-    _dm_hist[pos].outgoing = outgoing ? 1 : 0;
-    // Prefer the sender's own timestamp — a room-sync replay or an
-    // offline-queued message held by a repeater can arrive long after it was
-    // actually sent, so "now" would mislabel every backlog message as fresh.
-    // Fall back to receipt time only when the sender's timestamp is unknown.
-    _dm_hist[pos].timestamp = msg_ts ? msg_ts : rtc_clock.getCurrentTime();
-    strncpy(_dm_hist[pos].text, text, sizeof(DmHistEntry::text) - 1);
-    _dm_hist[pos].text[sizeof(DmHistEntry::text) - 1] = '\0';
-    _dm_hist[pos].ack_status      = (outgoing && ack_tag) ? ACK_PENDING : ACK_NONE;
-    _dm_hist[pos].ack_tag         = ack_tag;
-    _dm_hist[pos].ack_deadline_ms = ack_deadline_ms;
-    _dm_hist[pos].msg_ts          = msg_ts;
-    _dm_hist[pos].attempt         = 0;
-    _dm_hist[pos].resends_left    = (outgoing && ack_tag) ? resends : 0;
-  }
-
-  // Effective status for display. A pending ACK only reads as failed once its
-  // deadline has passed AND no auto-resends remain — while resends_left > 0 the
-  // entry stays pending (tickDmResends() retries / finalises it). Safety net for
-  // when the tick hasn't run yet; the tick is the authority that writes ACK_FAIL.
-  AckState dmEffectiveStatus(const DmHistEntry& e) const {
-    if (e.ack_status == ACK_PENDING && e.resends_left == 0 &&
-        (int32_t)(millis() - e.ack_deadline_ms) >= 0)
-      return ACK_FAIL;
-    return (AckState)e.ack_status;
-  }
-
-  int dmHistCountForContact(const uint8_t* prefix) const {
-    int n = 0;
-    for (int i = 0; i < _dm_hist_count; i++)
-      if (memcmp(_dm_hist[(_dm_hist_head + i) % DM_HIST_MAX].prefix, prefix, 4) == 0) n++;
-    return n;
-  }
-
-  int dmHistEntryForContact(const uint8_t* prefix, int j) const { // j=0 = newest
-    int n = 0;
-    for (int i = _dm_hist_count - 1; i >= 0; i--) {
-      int pos = (_dm_hist_head + i) % DM_HIST_MAX;
-      if (memcmp(_dm_hist[pos].prefix, prefix, 4) == 0) {
-        if (n == j) return pos;
-        n++;
-      }
-    }
-    return -1;
-  }
-
   void afterSend(bool ok, const char* msg) {
     _reply_mode = false;
     _share_mode = false;
@@ -453,21 +329,18 @@ class QuickMsgScreen : public UIScreen {
       int pos = addChannelMsg(_sel_channel_idx, entry);
       // Arm the "relayed into mesh" marker on this exact entry — MyMesh tracked
       // the flood it just originated and reports a heard repeater echo by seq.
-      if (pos >= 0) {
+      if (pos >= 0) _history.armChannelRelay(pos, the_mesh.lastChannelRelaySeq());
-        _hist[pos].relay_status = ACK_PENDING;
-        _hist[pos].relay_seq    = the_mesh.lastChannelRelaySeq();
-      }
       // After inserting sent msg at index 0, the unread index range is stale.
       // User is active in this channel — treat as fully read.
-      _ch_unread[_sel_channel_idx] = 0;
+      _history.setChUnread(_sel_channel_idx, 0);
       _unread_at_entry = 0;
       _viewing_max_seen = 0;
       _task->showAlert("Sent!", 600);
     } else if (ok) {
       NodePrefs* np = _task->getNodePrefs();
       uint8_t resends = np ? np->dm_resend_count : 0;
-      storeDMMsg(_sel_contact.id.pub_key, true, msg, _last_ack_tag,
+      _history.storeDMMsg(_sel_contact.id.pub_key, true, msg, _last_ack_tag,
-                 _last_ack_deadline_ms, _last_send_ts, resends);
+                          _last_ack_deadline_ms, _last_send_ts, resends);
       _dm_hist_sel = 0;
       _dm_hist_scroll = 0;
       _phase = DM_HIST;
@@ -522,7 +395,7 @@ class QuickMsgScreen : public UIScreen {
       for (int i = 0; i < total; i++) {
         if (!the_mesh.getContactByIdx(i, c) || c.type != ADV_TYPE_CHAT) continue;
         if (!show_all && !(c.flags & 0x01)) continue;
-        counts[_num_contacts] = dmHistCountForContact(c.id.pub_key);
+        counts[_num_contacts] = _history.dmHistCountForContact(c.id.pub_key);
         _sorted[_num_contacts++] = i;
       }
       // Sort by message count descending; contacts with no messages keep original order.
@@ -671,88 +544,25 @@ public:
       _msg_sel(0), _msg_scroll(0), _active_msg_count(0),
       _hist_sel(0), _hist_scroll(0),
       _unread_at_entry(0), _viewing_max_seen(0),
-      _hist_head(0), _hist_count(0),
-      _dm_hist_head(0), _dm_hist_count(0),
       _dm_hist_sel(-1), _dm_hist_scroll(0),
       _ctx_dirty(false), _pin_picker_active(false), _dm_direct_entry(false), _reply_mode(false) {
-    memset(_ch_unread, 0, sizeof(_ch_unread));
+    // The history rings + per-channel unread counters init in MessageHistory.
   }
 
-  // Returns the ring position the message was stored at, or -1 if rejected, so
+  // Public entry points (routed from MyMesh / the bot via UITask) — thin
-  // the outgoing path can attach a relay seq to that exact entry. `timestamp`
+  // forwarders to the history store. addChannelMsg computes the "viewing" flag
-  // is the sender's own send time (0 = unknown/outgoing — use receipt time);
+  // (a phase-machine fact the store can't see) and returns the ring position so
-  // see storeDMMsg() for why this matters for synced/queued backlog messages.
+  // the outgoing path can attach a relay seq to that exact entry.
   int addChannelMsg(uint8_t ch_idx, const char* text, uint32_t timestamp = 0) {
-    // Guard against bogus channel indices (e.g. findChannelIdx() returned -1
-    // and was cast to uint8_t → 255). Storing such an entry would burn a ring
-    // slot for a message that no visible channel can ever surface.
-    if (ch_idx >= MAX_GROUP_CHANNELS) return -1;
-    int pos;
-    if (_hist_count < CH_HIST_MAX) {
-      pos = (_hist_head + _hist_count) % CH_HIST_MAX;
-      _hist_count++;
-    } else {
-      pos = _hist_head;
-      // Evicting the oldest entry — drop its share of the unread counter so
-      // the badge can't claim a message the ring no longer holds.
-      uint8_t evicted = _hist[pos].ch_idx;
-      if (evicted < MAX_GROUP_CHANNELS && _ch_unread[evicted] > 0) {
-        _ch_unread[evicted]--;
-      }
-      _hist_head = (_hist_head + 1) % CH_HIST_MAX;
-    }
-    _hist[pos].ch_idx = ch_idx;
-    _hist[pos].timestamp = timestamp ? timestamp : rtc_clock.getCurrentTime();
-    strncpy(_hist[pos].text, text, sizeof(_hist[pos].text) - 1);
-    _hist[pos].text[sizeof(_hist[pos].text) - 1] = '\0';
-    _hist[pos].relay_status = ACK_NONE;
-    _hist[pos].relay_seq = 0;
-
     bool viewing = (_phase == CHANNEL_HIST && _sel_channel_idx == (int)ch_idx);
-    if (!viewing && _ch_unread[ch_idx] < 99) _ch_unread[ch_idx]++;
+    return _history.addChannelMsg(ch_idx, text, viewing, timestamp);
-    return pos;
   }
-
+  void markChannelRelayed(uint32_t seq) { _history.markChannelRelayed(seq); }
-  // Called when a repeater echo of one of our channel sends is heard.
-  void markChannelRelayed(uint32_t seq) {
-    if (seq == 0) return;
-    for (int i = 0; i < _hist_count; i++) {
-      ChHistEntry& e = _hist[(_hist_head + i) % CH_HIST_MAX];
-      if (e.relay_status == ACK_PENDING && e.relay_seq == seq) {
-        e.relay_status = ACK_OK;
-        return;
-      }
-    }
-  }
-
   void addDMMsg(const uint8_t* pub_key, bool outgoing, const char* text,
                 uint32_t sender_timestamp = 0) {
-    // Drop retried copies of an incoming DM: a resend reuses the sender's
+    _history.addDMMsg(pub_key, outgoing, text, sender_timestamp);
-    // timestamp and text but carries a fresh packet hash, so the mesh dup-filter
-    // lets it through. Match on prefix + sender_timestamp + text to suppress it.
-    if (!outgoing && sender_timestamp != 0) {
-      for (int i = 0; i < _dm_hist_count; i++) {
-        const DmHistEntry& e = _dm_hist[(_dm_hist_head + i) % DM_HIST_MAX];
-        if (!e.outgoing && e.msg_ts == sender_timestamp &&
-            memcmp(e.prefix, pub_key, 4) == 0 && strcmp(e.text, text) == 0)
-          return;  // duplicate retry — already in history
-      }
-    }
-    storeDMMsg(pub_key, outgoing, text, 0, 0, outgoing ? 0 : sender_timestamp, 0);
-  }
-
-  // Called when an end-to-end ACK arrives (routed from MyMesh::onAckRecv).
-  // Marks the matching pending outgoing DM as delivered.
-  void markDmDelivered(uint32_t ack_crc) {
-    if (ack_crc == 0) return;
-    for (int i = 0; i < _dm_hist_count; i++) {
-      DmHistEntry& e = _dm_hist[(_dm_hist_head + i) % DM_HIST_MAX];
-      if (e.outgoing && e.ack_status == ACK_PENDING && e.ack_tag == ack_crc) {
-        e.ack_status = ACK_OK;
-        return;
-      }
-    }
   }
+  void markDmDelivered(uint32_t ack_crc) { _history.markDmDelivered(ack_crc); }
 
   // Rooms successfully logged in to this power-on session. RAM-only — the
   // server's ACL (see ClientACL) is the real permission store and survives
@@ -810,55 +620,15 @@ public:
     _task->showAlert(success ? "Login OK" : "Login failed", 1200);
   }
 
-  // Look up a contact by 4-byte pub_key prefix (as stored in DmHistEntry).
-  bool contactByPrefix(const uint8_t* prefix, ContactInfo& out) const {
-    int total = the_mesh.getNumContacts();
-    for (int i = 0; i < total; i++) {
-      ContactInfo c;
-      if (the_mesh.getContactByIdx(i, c) && memcmp(c.id.pub_key, prefix, 4) == 0) {
-        out = c;
-        return true;
-      }
-    }
-    return false;
-  }
-
   // Background tick (called every UI loop, regardless of the active screen) that
-  // drives auto-resend of on-device DMs. When a pending DM passes its deadline
+  // drives auto-resend of on-device DMs — forwarded to the history store.
-  // with no ACK: resend with the next attempt# (reusing the original timestamp so
+  void tickDmResends() { _history.tickDmResends(); }
-  // the recipient dedups) while resends remain, else mark it failed (✗).
-  void tickDmResends() {
-    uint32_t now = millis();
-    for (int i = 0; i < _dm_hist_count; i++) {
-      DmHistEntry& e = _dm_hist[(_dm_hist_head + i) % DM_HIST_MAX];
-      if (!e.outgoing || e.ack_status != ACK_PENDING) continue;
-      if ((int32_t)(now - e.ack_deadline_ms) < 0) continue;   // still waiting
-      if (e.resends_left == 0) { e.ack_status = ACK_FAIL; continue; }
-      ContactInfo c;
-      if (!contactByPrefix(e.prefix, c)) { e.ack_status = ACK_FAIL; continue; }
-      uint32_t expected_ack = 0, est_timeout = 0;
-      uint8_t next_attempt = e.attempt + 1;
-      if (the_mesh.sendMessage(c, e.msg_ts, next_attempt, e.text,
-                               expected_ack, est_timeout) > 0 && expected_ack) {
-        e.attempt         = next_attempt;
-        e.ack_tag         = expected_ack;   // each attempt has a distinct ACK CRC
-        e.ack_deadline_ms = now + est_timeout + 4000;
-        e.resends_left--;
-      } else {
-        e.ack_status = ACK_FAIL;            // couldn't compose/send — give up
-      }
-    }
-  }
 
   int getDMUnreadTotal() const {
     return _task->getDMUnreadTotal();
   }
 
-  int getTotalChannelUnread() const {
+  int getTotalChannelUnread() const { return _history.getTotalChannelUnread(); }
-    int total = 0;
-    for (int i = 0; i < MAX_GROUP_CHANNELS; i++) total += _ch_unread[i];
-    return total;
-  }
 
   void markReadAlert(int n) {
     char msg[32];
@@ -866,10 +636,11 @@ public:
     _task->showAlert(msg, 800);
   }
 
-  void clearAllChannelUnread() {
+  void clearAllChannelUnread() { _history.clearAllChannelUnread(); }
-    memset(_ch_unread, 0, sizeof(_ch_unread));
-  }
 
+  // Update the viewing-session unread bookkeeping (UI state) and push the
+  // resulting count down into the store. The ring lives in _history, but this
+  // "what has the user seen on screen" logic is pure phase-machine state.
   void updateChannelUnread() {
     if (_sel_channel_idx < 0 || _sel_channel_idx >= MAX_GROUP_CHANNELS) return;
     // histEntryForChannel is newest-first: index 0 = newest (unread), higher = older.
@@ -881,7 +652,7 @@ public:
     if (seen_to > _viewing_max_seen) _viewing_max_seen = seen_to;
     // Each step down from 0 sees one more message; seen count = max_seen + 1.
     int remaining = _unread_at_entry - (_viewing_max_seen + 1);
-    _ch_unread[_sel_channel_idx] = (uint8_t)(remaining > 0 ? remaining : 0);
+    _history.setChUnread(_sel_channel_idx, (uint8_t)(remaining > 0 ? remaining : 0));
   }
 
   void reset() {
@@ -908,30 +679,9 @@ public:
     _viewing_max_seen = 0;
   }
 
-  // Recent DM contacts, newest first, deduped. Resolves the 4-byte
+  // Recent DM contacts, newest first, deduped (forwarded to the history store).
-  // _dm_hist prefix to a 6-byte pub_key prefix by walking the contact
-  // list once per unique sender. Returns the number filled.
   int getRecentDMContacts(uint8_t out[][NodePrefs::FAVOURITE_PREFIX_LEN], int max) const {
-    int n = 0;
+    return _history.getRecentDMContacts(out, max);
-    for (int i = _dm_hist_count - 1; i >= 0 && n < max; i--) {
-      int pos = (_dm_hist_head + i) % DM_HIST_MAX;
-      const uint8_t* p4 = _dm_hist[pos].prefix;
-      // Skip if already collected.
-      bool dup = false;
-      for (int j = 0; j < n; j++) if (memcmp(out[j], p4, 4) == 0) { dup = true; break; }
-      if (dup) continue;
-      // Find a real contact whose pub_key starts with this 4-byte prefix.
-      for (int idx = 0; ; idx++) {
-        ContactInfo c;
-        if (!the_mesh.getContactByIdx(idx, c)) break;
-        if (memcmp(c.id.pub_key, p4, 4) == 0) {
-          memcpy(out[n], c.id.pub_key, NodePrefs::FAVOURITE_PREFIX_LEN);
-          n++;
-          break;
-        }
-      }
-    }
-    return n;
   }
 
   // Jump straight into a contact's DM history (used by the Favourites dial).
@@ -1082,7 +832,7 @@ public:
         drawRowSelection(display, y, sel, reserve);
         ChannelDetails ch;
         if (the_mesh.getChannel(_channel_indices[list_idx], ch)) {
-          uint8_t unread = _ch_unread[_channel_indices[list_idx]];
+          uint8_t unread = _history.chUnread(_channel_indices[list_idx]);
           char badge[5] = "";
           int bw = 0;
           if (unread > 0) {
@@ -1106,21 +856,21 @@ public:
       display.translateUTF8ToBlocks(filtered_name, _sel_contact.name, sizeof(filtered_name));
 
       if (_dm_fs.active && _dm_hist_sel >= 0) {
-        int ring_pos = dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_sel);
+        int ring_pos = _history.dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_sel);
         if (ring_pos >= 0) {
-          const DmHistEntry& e = _dm_hist[ring_pos];
+          const DmHistEntry& e = _history.dmAtPos(ring_pos);
           char sender_buf[33];
           const char* body = dmDisplayParts(e, _sel_contact.type == ADV_TYPE_ROOM,
                                             filtered_name, sender_buf, sizeof(sender_buf));
           const char* sender = sender_buf;
-          int dm_count = dmHistCountForContact(_sel_contact.id.pub_key);
+          int dm_count = _history.dmHistCountForContact(_sel_contact.id.pub_key);
           int ret = _dm_fs.render(display, sender, body,
                                   _dm_hist_sel < dm_count - 1,
                                   _dm_hist_sel > 0);
           if (e.outgoing) {  // delivery marker in the (inverted) header bar
             display.setColor(DisplayDriver::DARK);
             drawAckGlyph(display, 2 + display.getTextWidth(sender) + 3, 1,
-                         dmEffectiveStatus(e), e.attempt + 1);
+                         _history.dmEffectiveStatus(e), e.attempt + 1);
             display.setColor(DisplayDriver::LIGHT);
           }
           if (_ctx_menu.active) _ctx_menu.render(display);
@@ -1138,7 +888,7 @@ public:
       display.drawTextCentered(display.width()/2, 0, title);
       display.fillRect(0, lh + 1, display.width(), display.sepH());
 
-      int dm_count = dmHistCountForContact(_sel_contact.id.pub_key);
+      int dm_count = _history.dmHistCountForContact(_sel_contact.id.pub_key);
       uint32_t now_ts = rtc_clock.getCurrentTime();
       bool is_room = (_sel_contact.type == ADV_TYPE_ROOM);
 
@@ -1153,8 +903,8 @@ public:
       HistScroll hs = computeHistScroll(display, portrait_expand, dm_count, _dm_hist_scroll,
           hist_start_y, cby, lh,
           [&](int idx) -> const char* {
-            int rp = dmHistEntryForContact(_sel_contact.id.pub_key, idx);
+            int rp = _history.dmHistEntryForContact(_sel_contact.id.pub_key, idx);
-            return rp >= 0 ? _dm_hist[rp].text : nullptr;
+            return rp >= 0 ? _history.dmAtPos(rp).text : nullptr;
           });
       int reserve = hs.reserve;
       {
@@ -1163,10 +913,10 @@ public:
         for (int ii = 0; ii < MAX_VIS_BOXES && (_dm_hist_scroll + ii) < dm_count; ii++) {
           int bh = fixed_bh;
           if (portrait_expand) {
-            int rp = dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_scroll + ii);
+            int rp = _history.dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_scroll + ii);
             if (rp >= 0) {
               char hsb[33];
-              const char* hbody = dmDisplayParts(_dm_hist[rp], is_room, filtered_name, hsb, sizeof(hsb));
+              const char* hbody = dmDisplayParts(_history.dmAtPos(rp), is_room, filtered_name, hsb, sizeof(hsb));
               display.translateUTF8ToBlocks(s_wrap_trans, hbody, sizeof(s_wrap_trans));
               int nl = FullscreenMsgView::wrapLines(display, s_wrap_trans, display.width() - 6 - reserve, s_wrap_lines, 8);
               bh = (1 + (nl > 0 ? nl : 1)) * lh + 1;
@@ -1184,10 +934,10 @@ public:
         int y = box_ys[i];
         int bh = box_hs[i];
 
-        int ring_pos = dmHistEntryForContact(_sel_contact.id.pub_key, item);
+        int ring_pos = _history.dmHistEntryForContact(_sel_contact.id.pub_key, item);
         if (ring_pos < 0) continue;
 
-        const DmHistEntry& e = _dm_hist[ring_pos];
+        const DmHistEntry& e = _history.dmAtPos(ring_pos);
         char sender_buf[33];
         const char* body = dmDisplayParts(e, is_room, filtered_name, sender_buf, sizeof(sender_buf));
         const char* sender = sender_buf;
@@ -1208,7 +958,7 @@ public:
         display.drawTextEllipsized(3, y + 1, display.width() - cw - 2 - age_w - reserve, sender);
         if (e.outgoing) {                       // delivery marker after "Me"
           int gx = 3 + display.getTextWidth(sender) + 3;
-          drawAckGlyph(display, gx, y + 1, dmEffectiveStatus(e), e.attempt + 1);
+          drawAckGlyph(display, gx, y + 1, _history.dmEffectiveStatus(e), e.attempt + 1);
         }
         if (age[0]) { display.setCursor(display.width() - age_w - reserve, y + 1); display.print(age); }
         if (!sel) display.setColor(DisplayDriver::LIGHT);
@@ -1248,10 +998,10 @@ public:
 
     } else if (_phase == CHANNEL_HIST) {
       if (_fs.active && _hist_sel >= 0) {
-        int fs_hist_count = histCountForChannel(_sel_channel_idx);
+        int fs_hist_count = _history.histCountForChannel(_sel_channel_idx);
-        int ring_pos = histEntryForChannel(_sel_channel_idx, _hist_sel);
+        int ring_pos = _history.histEntryForChannel(_sel_channel_idx, _hist_sel);
         if (ring_pos >= 0) {
-          const char* ftext = _hist[ring_pos].text;
+          const char* ftext = _history.chAtPos(ring_pos).text;
           const char* fsep = strstr(ftext, ": ");
           char fsender[33], fmsg[MSG_TEXT_BUF];
           if (fsep) {
@@ -1266,7 +1016,7 @@ public:
                                _hist_sel < fs_hist_count - 1,
                                _hist_sel > 0);
           // Channels: ✓ only once a repeater echo confirms relay (see list view).
-          if (strcmp(fsender, "Me") == 0 && _hist[ring_pos].relay_status == ACK_OK) {
+          if (strcmp(fsender, "Me") == 0 && _history.chAtPos(ring_pos).relay_status == ACK_OK) {
             display.setColor(DisplayDriver::DARK);
             drawAckGlyph(display, 2 + display.getTextWidth(fsender) + 3, 1, ACK_OK);
             display.setColor(DisplayDriver::LIGHT);
@@ -1287,7 +1037,7 @@ public:
       display.drawTextCentered(display.width()/2, 0, title);
       display.fillRect(0, lh + 1, display.width(), display.sepH());
 
-      int ch_hist_count = histCountForChannel(_sel_channel_idx);
+      int ch_hist_count = _history.histCountForChannel(_sel_channel_idx);
       uint32_t now_ts = rtc_clock.getCurrentTime();
 
       // Portrait e-ink (height > width): variable-height boxes that show the full
@@ -1299,9 +1049,9 @@ public:
       HistScroll hs = computeHistScroll(display, portrait_expand, ch_hist_count, _hist_scroll,
           hist_start_y, cby, lh,
           [&](int idx) -> const char* {
-            int rp = histEntryForChannel(_sel_channel_idx, idx);
+            int rp = _history.histEntryForChannel(_sel_channel_idx, idx);
             if (rp < 0) return nullptr;
-            const char* t = _hist[rp].text;
+            const char* t = _history.chAtPos(rp).text;
             const char* s = strstr(t, ": ");
             return s ? s + 2 : t;
           });
@@ -1312,9 +1062,9 @@ public:
         for (int ii = 0; ii < MAX_VIS_BOXES && (_hist_scroll + ii) < ch_hist_count; ii++) {
           int bh = fixed_bh;
           if (portrait_expand) {
-            int rp = histEntryForChannel(_sel_channel_idx, _hist_scroll + ii);
+            int rp = _history.histEntryForChannel(_sel_channel_idx, _hist_scroll + ii);
             if (rp >= 0) {
-              const char* rtext = _hist[rp].text;
+              const char* rtext = _history.chAtPos(rp).text;
               const char* rsep = strstr(rtext, ": ");
               const char* rbody = rsep ? rsep + 2 : rtext;
               display.translateUTF8ToBlocks(s_wrap_trans, skipReplyPrefix(rbody), sizeof(s_wrap_trans));
@@ -1336,10 +1086,10 @@ public:
         int y = box_ys[i];
         int bh = box_hs[i];
 
-        int ring_pos = histEntryForChannel(_sel_channel_idx, item);
+        int ring_pos = _history.histEntryForChannel(_sel_channel_idx, item);
         if (ring_pos < 0) continue;
 
-        const char* text = _hist[ring_pos].text;
+        const char* text = _history.chAtPos(ring_pos).text;
         const char* sep = strstr(text, ": ");
         char sender[33], msg_part[MSG_TEXT_BUF];
         if (sep) {
@@ -1353,7 +1103,7 @@ public:
           msg_part[sizeof(msg_part) - 1] = '\0';
         }
 
-        char age[6]; geo::fmtAgeShort(age, sizeof(age), now_ts, _hist[ring_pos].timestamp);
+        char age[6]; geo::fmtAgeShort(age, sizeof(age), now_ts, _history.chAtPos(ring_pos).timestamp);
         int age_w = age[0] ? display.getTextWidth(age) + 3 : 0;
 
         if (sel) {
@@ -1370,7 +1120,7 @@ public:
         // Channels have no recipient ACK — only show ✓ once a repeater echo
         // confirms the send was relayed into the mesh; otherwise no marker
         // (absence is normal, not a failure).
-        if (strcmp(sender, "Me") == 0 && _hist[ring_pos].relay_status == ACK_OK) {
+        if (strcmp(sender, "Me") == 0 && _history.chAtPos(ring_pos).relay_status == ACK_OK) {
           int gx = 3 + display.getTextWidth(sender) + 3;
           drawAckGlyph(display, gx, y + 1, ACK_OK);
         }
@@ -1710,8 +1460,8 @@ public:
           uint8_t ch_idx = _channel_indices[_channel_sel];
           int sel = _ctx_menu.selectedIndex();
           if (sel == 0) {
-            int cleared = (int)_ch_unread[ch_idx];
+            int cleared = (int)_history.chUnread(ch_idx);
-            _ch_unread[ch_idx] = 0;
+            _history.setChUnread(ch_idx, 0);
             markReadAlert(cleared);
           }
           // sel 1/2/3 already handled by LEFT/RIGHT; ENTER just closes.
@@ -1726,8 +1476,8 @@ public:
       if (c == KEY_ENTER && _num_channels > 0) {
         _sel_channel_idx = _channel_indices[_channel_sel];
         if (_pick_target) { commitPickTargetChannel(_sel_channel_idx); return true; }
-        int hc = histCountForChannel(_sel_channel_idx);
+        int hc = _history.histCountForChannel(_sel_channel_idx);
-        _unread_at_entry = (int)_ch_unread[_sel_channel_idx];
+        _unread_at_entry = (int)_history.chUnread(_sel_channel_idx);
         _hist_scroll = 0;
         _hist_sel = hc > 0 ? 0 : -1;
         _viewing_max_seen = _hist_sel >= 0 ? _hist_sel : 0;
@@ -1760,7 +1510,7 @@ public:
       }
 
     } else if (_phase == DM_HIST) {
-      int dm_count = dmHistCountForContact(_sel_contact.id.pub_key);
+      int dm_count = _history.dmHistCountForContact(_sel_contact.id.pub_key);
       if (_dm_fs.active) {
         if (_ctx_menu.active) {
           auto res = _ctx_menu.handleInput(c);
@@ -1779,11 +1529,11 @@ public:
         } else if (res == FullscreenMsgView::CLOSE) {
           _dm_fs.active = false;
         } else if (res == FullscreenMsgView::REPLY) {
-          int ring_pos = dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_sel);
+          int ring_pos = _history.dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_sel);
           if (ring_pos >= 0) {
-            bool reply_ok = !_dm_hist[ring_pos].outgoing;
+            bool reply_ok = !_history.dmAtPos(ring_pos).outgoing;
-            if (reply_ok) buildDmReplyPrefix(_dm_hist[ring_pos]);
+            if (reply_ok) buildDmReplyPrefix(_history.dmAtPos(ring_pos));
-            buildFsMenu(_dm_hist[ring_pos].text, reply_ok);
+            buildFsMenu(_history.dmAtPos(ring_pos).text, reply_ok);
           }
         }
         return true;
@@ -1835,17 +1585,17 @@ public:
         return true;
       }
       if (c == KEY_CONTEXT_MENU && _dm_hist_sel >= 0) {
-        int ring_pos = dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_sel);
+        int ring_pos = _history.dmHistEntryForContact(_sel_contact.id.pub_key, _dm_hist_sel);
         if (ring_pos >= 0) {
-          bool reply_ok = !_dm_hist[ring_pos].outgoing;
+          bool reply_ok = !_history.dmAtPos(ring_pos).outgoing;
-          if (reply_ok) buildDmReplyPrefix(_dm_hist[ring_pos]);
+          if (reply_ok) buildDmReplyPrefix(_history.dmAtPos(ring_pos));
-          buildFsMenu(_dm_hist[ring_pos].text, reply_ok);
+          buildFsMenu(_history.dmAtPos(ring_pos).text, reply_ok);
         }
         return true;
       }
 
     } else if (_phase == CHANNEL_HIST) {
-      int ch_hist_count = histCountForChannel(_sel_channel_idx);
+      int ch_hist_count = _history.histCountForChannel(_sel_channel_idx);
       if (_fs.active) {
         if (_ctx_menu.active) {
           auto res = _ctx_menu.handleInput(c);
@@ -1864,9 +1614,9 @@ public:
         } else if (res == FullscreenMsgView::CLOSE) {
           _fs.active = false;
         } else if (res == FullscreenMsgView::REPLY) {
-          int ring_pos = histEntryForChannel(_sel_channel_idx, _hist_sel);
+          int ring_pos = _history.histEntryForChannel(_sel_channel_idx, _hist_sel);
           if (ring_pos >= 0)
-            buildFsMenu(_hist[ring_pos].text, buildChannelReplyPrefix(_hist[ring_pos].text));
+            buildFsMenu(_history.chAtPos(ring_pos).text, buildChannelReplyPrefix(_history.chAtPos(ring_pos).text));
         }
         return true;
       }
@@ -1907,9 +1657,9 @@ public:
         return true;
       }
       if (c == KEY_CONTEXT_MENU && _hist_sel >= 0) {
-        int ring_pos = histEntryForChannel(_sel_channel_idx, _hist_sel);
+        int ring_pos = _history.histEntryForChannel(_sel_channel_idx, _hist_sel);
         if (ring_pos >= 0)
-          buildFsMenu(_hist[ring_pos].text, buildChannelReplyPrefix(_hist[ring_pos].text));
+          buildFsMenu(_history.chAtPos(ring_pos).text, buildChannelReplyPrefix(_history.chAtPos(ring_pos).text));
         return true;
       }
 

examples/companion_radio/ui-new/UITask.cpp

@@ -130,6 +130,7 @@ static const int QUICK_MSGS_MAX = 10;
 #include "FullscreenMsgView.h"
 #include "SensorPlaceholders.h"
 #include "SettingsScreen.h"
+#include "MessageHistory.h"   // RAM history rings (DM + channel) used by QuickMsgScreen
 #include "QuickMsgScreen.h"
 
 // ── Custom screens (separate files to ease upstream merges) ───────────────────