feat(ui): discoverable context-menu hint — header glyph, highlight, corner dropdown

Hold-Enter context menus were invisible. Add a menu affordance to every screen
that has one:

- A small ≡ glyph in the header's top-right, via new DisplayDriver::
  drawContextMenuHint() and an optional menu_hint arg on drawCenteredHeader() /
  drawInvertedHeader() (reserves the corner so the title never runs under it).
- The glyph highlights (corner cell filled, bars knocked out) while the menu is
  open, tying the hint to the popup it spawned — driven by a menu_open flag the
  screens pass from their live popup state.
- The context menu now drops out of that corner: PopupMenu gains an opt-in
  top-right anchor (begin(..., anchor_top_right)); it right-aligns under the
  header instead of centring, so the menu reads as emerging from the ≡. Default
  stays centred, so non-context popups (Tools/Settings/etc.) are untouched.

Enabled on Nodes (list/scan/detail) and Messages (mode select, contact/room and
channel pickers, DM and channel history).

Both solo envs build green.

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

examples/companion_radio/ui-new/NearbyScreen.h

@@ -415,7 +415,7 @@ class NearbyScreen : public UIScreen {
   void startDeleteConfirm() {
     const Entry* e = selected();
     if (!e || !e->has_key || !entryIsContact(e)) return;
-    _confirm.begin("Delete contact?", 2);
+    _confirm.begin("Delete contact?", 2, true);
     _confirm.addItem("Delete");
     _confirm.addItem("Cancel");
     _confirm.setSelected(1);
@@ -451,7 +451,7 @@ class NearbyScreen : public UIScreen {
 
   void rebuildPingMenu() {
     int keep = _ping_menu.selectedIndex();  // preserve selection across a rebuild
-    _ping_menu.begin("Ping", 4);
+    _ping_menu.begin("Ping", 4, true);
     _ping_menu.addItem("Send");
     if (_ping_time_str[0])      _ping_menu.addItem(_ping_time_str);
     if (_ping_snr_out_str[0])   _ping_menu.addItem(_ping_snr_out_str);
@@ -543,7 +543,7 @@ class NearbyScreen : public UIScreen {
 
     buildSortLabel();
     _menu_action_count = 0;
-    _menu.begin("Options", 10);
+    _menu.begin("Options", 10, true);
     auto add = [&](const char* label, Action a) {
       _menu.addItem(label);
       _menu_actions[_menu_action_count++] = a;
@@ -611,7 +611,7 @@ class NearbyScreen : public UIScreen {
   void renderStoredDetail(DisplayDriver& display) {
     const Entry& e = _entries[_sel];
     const int hdr  = display.listStart();   // content top (gap below the header separator)
-    display.drawInvertedHeader(e.name);
+    display.drawInvertedHeader(e.name, true, ctxMenuOpen());
 
     int step = display.lineStep();
     if (step * 5 > display.height() - hdr) step = (display.height() - hdr) / 5;
@@ -648,7 +648,7 @@ class NearbyScreen : public UIScreen {
     char label[32];
     if (e.name[0]) { strncpy(label, e.name, 31); label[31] = '\0'; }
     else           { snprintf(label, sizeof(label), "[%s]", typeName(e.type)); }
-    display.drawInvertedHeader(label);
+    display.drawInvertedHeader(label, true, ctxMenuOpen());
 
     char b64[48];
     pubKeyToBase64(e.pub_key, b64, sizeof(b64));
@@ -679,6 +679,10 @@ class NearbyScreen : public UIScreen {
     display.print(e.is_known ? "Status: known" : "Status: new");
   }
 
+  // Any Hold-Enter popup on screen → highlight the ≡ hint so it reads as the
+  // source of the open menu.
+  bool ctxMenuOpen() const { return _menu.active || _confirm.active || _ping_menu.active; }
+
   // Draw whichever popup is active over the current view. Returns true if one was.
   bool renderActivePopup(DisplayDriver& display) {
     updatePingMenuState();
@@ -719,6 +723,7 @@ class NearbyScreen : public UIScreen {
 
     int lx = ax - gap;                                // next left tab's right edge
     int rx = ax + w[_filter] + gap;                   // next right tab's left edge
+    int rx_limit = display.width() - display.menuHintWidth();  // leave room for the ≡ hint
     bool lfit = true, rfit = true;
     for (int k = 1; k <= F_COUNT / 2 && (lfit || rfit); k++) {
       int li = (_filter - k + F_COUNT) % F_COUNT;
@@ -731,12 +736,13 @@ class NearbyScreen : public UIScreen {
       // Skip the right side when it lands on the same tab as the left (the single
       // opposite tab on an even count) so it isn't drawn twice.
       if (rfit && ri != li) {
-        if (rx + w[ri] <= display.width()) { drawTab(display, rx, w[ri], FILTER_LABELS[ri], false); rx += w[ri] + gap; }
+        if (rx + w[ri] <= rx_limit) { drawTab(display, rx, w[ri], FILTER_LABELS[ri], false); rx += w[ri] + gap; }
         else rfit = false;
       }
     }
     display.setColor(DisplayDriver::LIGHT);
     display.fillRect(0, display.headerH() - display.sepH(), display.width(), display.sepH());
+    display.drawContextMenuHint(DisplayDriver::LIGHT, ctxMenuOpen());   // Nodes list has a Hold-Enter menu
   }
 
 public:
@@ -825,7 +831,7 @@ public:
       } else if (_scanning)            snprintf(title, sizeof(title), "SCANNING (%d)", _count);
       else if (_count == 0)            snprintf(title, sizeof(title), "SCAN: none");
       else                             snprintf(title, sizeof(title), "SCAN (%d)", _count);
-      display.drawCenteredHeader(title);
+      display.drawCenteredHeader(title, true, ctxMenuOpen());
     } else {
       // Stored list: the filter is a visible tab strip (LEFT/RIGHT switches tabs).
       drawFilterTabs(display);

examples/companion_radio/ui-new/PopupMenu.h

@@ -17,14 +17,16 @@ struct PopupMenu {
   int         _cap;       // actual visible cap, updated each render()
   bool        active;
   const char* _title;
+  bool        anchor_tr = false;  // opt-in: drop from the top-right ≡ hint instead of centring
 
   enum Result { NONE, SELECTED, CANCELLED };
 
   PopupMenu() : _count(0), _sel(0), _scroll(0), _visible(3), _cap(3), active(false), _title(nullptr) {}
 
-  void begin(const char* title, int visible = 3) {
+  void begin(const char* title, int visible = 3, bool anchor_top_right = false) {
     _count = 0; _sel = 0; _scroll = 0;
     _visible = visible; _cap = visible; active = true; _title = title;
+    anchor_tr = anchor_top_right;
   }
 
   void addItem(const char* item) {
@@ -86,8 +88,17 @@ struct PopupMenu {
     int bh = title_h + vis * item_h + 1;   // +1 keeps the last row off the bottom border
 
     // Centre on screen (clamped to the margins on small displays).
-    int bx = (display.width()  - bw) / 2;
+    int bx, by;
-    int by = (display.height() - bh) / 2;
+    if (anchor_tr) {
+      // Drop out of the top-right ≡ hint: right-aligned under the header, so the
+      // menu reads as emerging from the glyph that spawned it.
+      bx = display.width() - bw - margin;
+      by = display.headerH();
+      if (by + bh > display.height() - margin) by = display.height() - margin - bh;
+    } else {
+      bx = (display.width()  - bw) / 2;
+      by = (display.height() - bh) / 2;
+    }
     if (bx < margin) bx = margin;
     if (by < margin) by = margin;
 

examples/companion_radio/ui-new/QuickMsgScreen.h

@@ -255,7 +255,7 @@ class QuickMsgScreen : public UIScreen {
     int n = (reply_allowed ? 1 : 0) + (has_loc ? 2 : 0);
     if (n == 0) return;
     _fs_act_n = 0;
-    _ctx_menu.begin("Options", n);
+    _ctx_menu.begin("Options", n, true);
     if (reply_allowed) { _ctx_menu.addItem("Reply");         _fs_act[_fs_act_n++] = FS_REPLY; }
     if (has_loc)       { _ctx_menu.addItem("Navigate");      _fs_act[_fs_act_n++] = FS_NAV;
                          _ctx_menu.addItem("Save waypoint"); _fs_act[_fs_act_n++] = FS_SAVE; }
@@ -791,7 +791,7 @@ public:
     int cw      = display.getCharWidth();
 
     if (_phase == MODE_SELECT) {
-      display.drawCenteredHeader("MESSAGE");
+      display.drawCenteredHeader("MESSAGE", true, _ctx_menu.active);
       const char* opts[] = { "Direct message", "Channels", "Room Servers" };
       int badges[3] = {
         getDMUnreadTotal(),
@@ -811,7 +811,7 @@ public:
       if (_ctx_menu.active) _ctx_menu.render(display);
 
     } else if (_phase == CONTACT_PICK) {
-      display.drawCenteredHeader(_room_mode ? "SELECT ROOM" : "SELECT CONTACT");
+      display.drawCenteredHeader(_room_mode ? "SELECT ROOM" : "SELECT CONTACT", true, _ctx_menu.active);
 
       if (_num_contacts == 0) {
         display.drawTextCentered(display.width()/2, display.height()/2, _room_mode ? "No room servers" : "No favourites");
@@ -839,7 +839,7 @@ public:
       if (_ctx_menu.active) _ctx_menu.render(display);
 
     } else if (_phase == CHANNEL_PICK) {
-      display.drawCenteredHeader("SELECT CHANNEL");
+      display.drawCenteredHeader("SELECT CHANNEL", true, _ctx_menu.active);
 
       if (_num_channels == 0) {
         display.drawTextCentered(display.width()/2, display.height()/2, "No channels");
@@ -895,7 +895,7 @@ public:
 
       char title[24];
       snprintf(title, sizeof(title), "%.23s", filtered_name);
-      display.drawCenteredHeader(title);
+      display.drawCenteredHeader(title, true, _ctx_menu.active);
 
       int dm_count = _history.dmHistCountForContact(_sel_contact.id.pub_key);
       uint32_t now_ts = rtc_clock.getCurrentTime();
@@ -1024,7 +1024,7 @@ public:
       the_mesh.getChannel(_sel_channel_idx, ch);
       char title[24];
       snprintf(title, sizeof(title), "%.23s", ch.name);
-      display.drawCenteredHeader(title);
+      display.drawCenteredHeader(title, true, _ctx_menu.active);
 
       int ch_hist_count = _history.histCountForChannel(_sel_channel_idx);
       uint32_t now_ts = rtc_clock.getCurrentTime();
@@ -1200,7 +1200,7 @@ public:
       if (c == KEY_CONTEXT_MENU) {
         // PopupMenu stores the title pointer verbatim — use static strings.
         static const char* MODE_TITLES[] = { "DM options", "Channel options", "Room options" };
-        _ctx_menu.begin(MODE_TITLES[_mode_sel < 3 ? _mode_sel : 0], 1);
+        _ctx_menu.begin(MODE_TITLES[_mode_sel < 3 ? _mode_sel : 0], 1, true);
         _ctx_menu.addItem("Mark all read");
         return true;
       }
@@ -1314,7 +1314,7 @@ public:
                     snprintf(_pin_slot_labels[s], sizeof(_pin_slot_labels[s]), "Slot %d: %s", s + 1, nm);
                   }
                 }
-                _ctx_menu.begin("Pick slot", 3);
+                _ctx_menu.begin("Pick slot", 3, true);
                 for (int s = 0; s < NodePrefs::FAVOURITES_COUNT; s++) _ctx_menu.addItem(_pin_slot_labels[s]);
                 _pin_picker_active = true;
               }
@@ -1355,7 +1355,7 @@ public:
         return true;
       }
       if (c == KEY_CONTEXT_MENU && _num_contacts > 0 && _room_mode) {
-        _ctx_menu.begin("Room options", 1);
+        _ctx_menu.begin("Room options", 1, true);
         _ctx_menu.addItem("Login...");
         return true;
       }
@@ -1371,7 +1371,7 @@ public:
         int pinned_slot = _task->findFavouriteSlot(ci.id.pub_key);
         if (pinned_slot >= 0) snprintf(_ctx_pin_item, sizeof(_ctx_pin_item), "Unpin (slot %d)", pinned_slot + 1);
         else                  snprintf(_ctx_pin_item, sizeof(_ctx_pin_item), "Pin to dial");
-        _ctx_menu.begin("Contact options", 3);
+        _ctx_menu.begin("Contact options", 3, true);
         _ctx_menu.addItem("Mark as read");
         _ctx_menu.addItem(_ctx_notif_item);
         _ctx_menu.addItem(_ctx_melody_item);
@@ -1471,7 +1471,7 @@ public:
         { NodePrefs* p2 = _task->getNodePrefs();
           bool is_fav = p2 && (p2->ch_fav_bitmask & (1ULL << ch_idx));
           snprintf(_ctx_ch_fav_item, sizeof(_ctx_ch_fav_item), is_fav ? "Fav: yes" : "Fav: no"); }
-        _ctx_menu.begin("Channel options", 4);
+        _ctx_menu.begin("Channel options", 4, true);
         _ctx_menu.addItem("Mark all read");
         _ctx_menu.addItem(_ctx_notif_item);
         _ctx_menu.addItem(_ctx_melody_item);

src/helpers/ui/DisplayDriver.h

@@ -207,23 +207,52 @@ public:
   // Inverted title bar: light background, dark ellipsized label, then the
   // standard separator line. The label is UTF-8 translated by
   // drawTextEllipsized. Leaves ink colour LIGHT for following content.
-  void drawInvertedHeader(const char* label) {
+  // Pixel width the ≡ context-menu hint reserves at the header's right edge.
+  int menuHintWidth() const { return getCharWidth() + 3; }
+
+  // Small ≡ glyph at the header's top-right, signalling the screen has a
+  // Hold-Enter context menu. Three stacked bars, drawn in colour c (LIGHT on a
+  // plain header, DARK on an inverted bar). When active (the menu is open) the
+  // corner cell is highlighted and the bars knocked out, tying the glyph to the
+  // popup it spawned. Call after the header body.
+  void drawContextMenuHint(Color c = LIGHT, bool active = false) {
+    int gw = getCharWidth() + 1;
+    int gx = width() - gw - 1;
+    int th = sepH();
+    int gy = (getLineHeight() - (th * 3 + 4)) / 2;
+    if (gy < 0) gy = 0;
+    Color bars = c;
+    if (active) {
+      setColor(c);
+      fillRect(gx - 1, 0, gw + 2, headerH() - sepH());
+      bars = (c == LIGHT) ? DARK : LIGHT;
+    }
+    setColor(bars);
+    for (int i = 0; i < 3; i++) fillRect(gx, gy + i * (th + 2), gw, th);
+    setColor(LIGHT);
+  }
+
+  void drawInvertedHeader(const char* label, bool menu_hint = false, bool menu_open = false) {
     int hdr = headerH();
     setColor(LIGHT);
     fillRect(0, 0, width(), hdr - 1);
+    int reserve = menu_hint ? menuHintWidth() : 0;
     setColor(DARK);
-    drawTextEllipsized(2, 1, width() - 4, (label && label[0]) ? label : "");
+    drawTextEllipsized(2, 1, width() - 4 - reserve, (label && label[0]) ? label : "");
+    if (menu_hint) drawContextMenuHint(DARK, menu_open);
     setColor(LIGHT);
     fillRect(0, hdr - 1, width(), sepH());
   }
 
   // Centred screen title + bottom separator line — the standard top bar for
   // full-screen list/detail views. Leaves ink LIGHT; callers can draw extra
-  // header content (counters, etc.) afterwards.
+  // header content (counters, etc.) afterwards. menu_hint adds the ≡ glyph;
-  void drawCenteredHeader(const char* title) {
+  // menu_open highlights it while the context menu is on screen.
+  void drawCenteredHeader(const char* title, bool menu_hint = false, bool menu_open = false) {
     setColor(LIGHT);
     drawTextCentered(width() / 2, 0, title);
     fillRect(0, headerH() - sepH(), width(), sepH());
+    if (menu_hint) drawContextMenuHint(LIGHT, menu_open);
   }
 
   // Advance a UTF-8 pointer by one codepoint, returning the decoded value.