feat(ui): mark-all-read context menu on MESSAGE mode-select

Hold Enter (context menu) on the DM / Channels / Rooms picker opens a
single-item "Mark all read" menu that clears every unread counter of
the highlighted type. Per-mode title is a static-const string because
PopupMenu stores the title pointer verbatim.

New UITask::clearAllDMUnread() resets the whole _dm_unread_table;
clearAllChannelUnread() and clearRoomUnread() already existed.

Also document the GPS breadcrumb storage decision in FEATURES.md:
RAM-only ring with explicit per-slot saves, no background flash writes.

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

FEATURES.md

@@ -0,0 +1,219 @@
+# Feature roadmap
+
+Joystick-only UX constraints: 4 directions + Enter + Back. No text entry except inside KeyboardWidget. Everything else navigable with cursor + press.
+
+Status legend: 📋 planned · 🚧 in progress · ✅ done · ❌ rejected/deferred
+
+---
+
+## Priority queue
+
+### ✅ Mark-all-read at type level
+
+Hold Enter on the MESSAGE mode-select screen (DM / Channels / Rooms) opens a 1-item context menu "Mark all read". Acts on the currently highlighted mode and shows a brief confirmation alert.
+
+Implementation:
+- New `UITask::clearAllDMUnread()` — `memset` over `_dm_unread_table`
+- `QuickMsgScreen::clearAllChannelUnread()` already existed
+- `UITask::clearRoomUnread()` already existed
+- Title is a `static const char*` table (PopupMenu stores the title pointer verbatim — locals would dangle)
+- Zero schema impact, all counters live in RAM
+
+### 📋 Favourites dial
+
+📋 planned
+
+A 2×3 grid (six slots) of pinned contacts on its own home page, between Clock and Messages. Joystick picks a tile, Enter opens the existing DM conversation or sends a pre-set quick reply.
+
+Data model:
+- New field in NodePrefs: `uint8_t favourite_contacts[6][6]` — first 6 bytes of each contact's `pub_key` (enough to disambiguate locally)
+- Lookup at render time: walk contacts, match prefix, render name + unread badge
+- Empty slot renders as "+" placeholder; Enter on empty opens a contact picker (existing UI)
+
+Pinning UX:
+- In QuickMsg DM list, long-press on a contact → context menu → "Pin to dial" → asks which of the 6 slots
+- Unpin via the same menu (only shown when contact is already pinned)
+
+Schema bump: add `favourite_contacts` to NodePrefs, bump `SCHEMA_SENTINEL` low byte.
+
+Render layout (250×122 landscape e-ink):
+```
+╔══════════════════════════════╗
+║ Favourites                   ║
+╠══════════════════════════════╣
+║ ┌──────┐ ┌──────┐ ┌──────┐   ║
+║ │Alice │ │Bob 3 │ │  +   │   ║
+║ └──────┘ └──────┘ └──────┘   ║
+║ ┌──────┐ ┌──────┐ ┌──────┐   ║
+║ │Carol │ │  +   │ │  +   │   ║
+║ └──────┘ └──────┘ └──────┘   ║
+╚══════════════════════════════╝
+```
+
+Joystick navigation is natural with 6 tiles (UP/DOWN between rows, LEFT/RIGHT within row).
+
+### 📋 GPS breadcrumb
+
+📋 planned
+
+Tools › Breadcrumb. Periodically samples `(lat, lon, ts)` into a RAM ring buffer; user explicitly saves snapshots to flash.
+
+**Storage model — RAM ring with explicit save**
+
+Rationale: auto-off only blanks the display, the firmware keeps running, so the RAM trail survives every idle scenario. Typical use is a single trip start→stop while wearing the device; persisting across reboots is rarely wanted. RAM-only avoids ~1400 flash writes/day and the LittleFS wear that comes with continuous logging.
+
+- Live ring: `BreadcrumbEntry[BC_RAM_CAP]` in `UITask` (or a dedicated component). Each entry `int32_t lat_1e6, int32_t lon_1e6, uint32_t ts` = 12 B. Cap = 256 → 3 KB RAM. nRF52840 (256 KB RAM) has plenty of headroom.
+- Wrap-on-write: oldest entry replaced when buffer full.
+- Reboot wipes the live trail (intentional; matches the "this trip" model).
+
+**Snapshot slots on flash** (user-initiated only):
+- `/breadcrumb.0`, `/breadcrumb.1`, `/breadcrumb.2` — three named slots
+- Each file: small header (count, start_ts, end_ts, total_distance_m) + entry array
+- Written only on explicit "Save trail" action — zero background writes, zero wear concern
+- Optional: auto-save to slot 0 on detected low-battery shutdown (single write before going dark)
+
+UI screens (LEFT/RIGHT cycles):
+1. **Summary** — total distance (km), elapsed time (h:mm), point count, current speed (from last 2 samples), GPS fix indicator
+2. **Trail map** — ASCII bounding-box plot. Auto-fit the polygon, current position marked `X`, start marked `*`. UP/DOWN zoom, LEFT/RIGHT pan when zoomed.
+3. **Last N entries list** — scroll through recent points with timestamp + delta from previous.
+
+Joystick actions:
+- Enter → toggle live logging on/off (status bar shows `*` when active, like auto-advert `A`)
+- Back → exit
+- Hold Enter → context menu:
+  - "Reset trail" — clear RAM ring
+  - "Save trail → slot N" — snapshot RAM into chosen flash slot
+  - "Load trail ← slot N" — restore from chosen slot into RAM ring
+  - "Export over USB" — dump live RAM trail as KML/GPX over serial
+
+Statistics computed on the fly walking the ring:
+- Total distance: sum of Haversine(p[i], p[i-1])
+- Elapsed time: ts[last] - ts[first]
+- Current speed: dist(last, prev) / (ts[last] - ts[prev])
+
+Settings:
+- Settings › GPS › Breadcrumb interval: off / 30 s / 1 min / 5 min / 15 min (default 1 min)
+- Settings › GPS › Breadcrumb min delta: 5 m / 25 m / 100 m (skip near-stationary samples to keep the ring densely populated with real movement)
+
+Schema impact: new prefs fields `uint8_t breadcrumb_interval_idx`, `uint8_t breadcrumb_min_delta_idx`. Sentinel bump. The slot files are separate from prefs.
+
+Edge cases:
+- No GPS fix: skip sampling, status indicator dims
+- Low-batt shutdown: optional auto-save to slot 0 (one write) before powerdown
+- Memory: 3 KB RAM is negligible on this MCU; if RAM ever tightens, drop to 128 entries
+
+---
+
+## Backlog (not yet prioritised)
+
+### Compass to contact
+
+Select contact in Nearby → Enter → fullscreen compass. Arrow points to last-known position of contact relative to my GPS heading (need accel/mag or compute heading from movement). Distance below. Updates every 1 s.
+
+Joystick: Enter from Nearby toggles, Back exits. Heading-from-GPS requires moving; for stationary use, would need magnetometer that the L1 board does or doesn't have — check.
+
+### SOS broadcast
+
+Configurable in Settings › System › SOS:
+- Target: channel index or DM contact
+- Message template (uses placeholders)
+
+Trigger: Hold Back + Hold Enter for 3 s on any screen → confirmation popup ("Send SOS?") → Enter to send. Sends with `{loc}` and `{batt}` filled. 30 s cooldown.
+
+### Range test
+
+Tools › Range Test:
+- Pick a node from contacts/nearby
+- Enter starts pinging every 5 s, logs RTT + RSSI + SNR (ring ~30)
+- Display shows current values + 30-sample sparkline (block characters)
+- Enter stops; Hold Enter for context menu (reset, change target)
+
+### Quiet hours
+
+Settings › Sound › Quiet Hours:
+- Enable on/off
+- Start HH (LEFT/RIGHT to change, 24 h)
+- End HH
+
+When within window: buzzer set to "off" (overrides setting), display brightness → 0. Restores prefs values when window ends. Time source: rtc_clock.
+
+### Channel scanner home page
+
+Toggleable in Settings › Home Pages. Lists channels with: name, unread count, last message age. Enter opens the channel. Sort by recency by default; LEFT/RIGHT toggles to alphabetical.
+
+### Contact distance sort
+
+QuickMsg DM list: a 4-th sort mode (currently sorted by message count). LEFT/RIGHT on the list header cycles: name | message-count | recency | distance. Distance uses GPS pos from contact's last advert.
+
+### Signal stats screen
+
+Tools › Stats:
+- Battery voltage 60-min sparkline
+- RSSI of last 30 received packets
+- Noise floor current
+- Free heap (if available)
+
+Read-only. UP/DOWN switches between metrics. Bottom shows current value as text.
+
+### Auto-reply trigger words with sensor placeholders
+
+Bot already has a single trigger word. Extend to a small table of (trigger, reply-with-placeholder) pairs:
+- "temp?" → replies with `{temp}`
+- "loc?" → replies with `{loc}`
+- "batt?" → replies with `{batt}`
+
+Stored in NodePrefs as fixed-size table (say 4 pairs × 16 B). UI: edit pairs in Tools › Auto-Reply Bot.
+
+### Lock-screen unread count
+
+Show `12 new` or two-line `5 DM / 7 ch` on lock screen below the time. Reuses existing `_hist`/`_dm_hist` unread counters. Cosmetic only, no schema change.
+
+### Power profile presets
+
+Settings › Profile: Indoor / Outdoor / Expedition. Each pre-fills:
+- Auto-off seconds
+- GPS interval
+- Auto-advert interval
+- Brightness
+
+Single Enter applies. Stored as `uint8_t profile_idx` with hardcoded value tables.
+
+### Battery curve calibration
+
+Settings › System › Batt Calibration: edit 5 voltage breakpoints used to convert mV → %. UP/DOWN selects breakpoint, LEFT/RIGHT changes voltage in 50 mV steps. Helps users with non-standard LiPos report accurate %.
+
+### Mark-read at type level — already covered above as priority
+
+### Display test pattern
+
+Tools › Display Test: full-screen grid + bars + Lemon glyph dump. Useful for verifying driver/font changes after flashing.
+
+### Group "who's online" ping
+
+From channel view, Hold Enter → "Who's online?". Sends 0-hop discovery to channel members, collects responses for 10 s, shows a list with RSSI. Similar to existing Nearby active discovery but scoped to a channel.
+
+---
+
+## Deferred
+
+### ❌ Morse keyboard
+
+Cute but niche. Skip unless explicitly requested.
+
+### ❌ Buzzer EVENTS_STOPPED IRQ chaining
+
+Marginal real-world gain (2 ms between notes during melody playback only), high risk on the PWM peripheral.
+
+### ❌ Vibration feedback
+
+Wio Tracker L1 doesn't have a haptic motor. N/A.
+
+---
+
+## Implementation order suggestion
+
+1. **Mark-all-read** — smallest patch, biggest day-to-day comfort gain
+2. **Favourites dial** — new home page + new prefs field; touches familiar areas (QuickMsg context menu, NodePrefs, schema sentinel bump)
+3. **GPS breadcrumb** — largest of the three; introduces a new flash file and a Tools sub-screen with multiple views
+
+After #3, re-prioritise the backlog with the user.

examples/companion_radio/ui-new/QuickMsgScreen.h

@@ -505,6 +505,7 @@ public:
         }
       }
       display.setColor(DisplayDriver::LIGHT);
+      if (_ctx_menu.active) _ctx_menu.render(display);
 
     } else if (_phase == CONTACT_PICK) {
       display.drawTextCentered(display.width()/2, 0, _room_mode ? "SELECT ROOM" : "SELECT CONTACT");
@@ -860,9 +861,33 @@ public:
 
   bool handleInput(char c) override {
     if (_phase == MODE_SELECT) {
+      // Context menu (Mark-all-read) takes precedence while active.
+      if (_ctx_menu.active) {
+        auto res = _ctx_menu.handleInput(c);
+        if (res == PopupMenu::SELECTED) {
+          if (_mode_sel == 0) {
+            _task->clearAllDMUnread();
+            _task->showAlert("DMs marked read", 800);
+          } else if (_mode_sel == 1) {
+            clearAllChannelUnread();
+            _task->showAlert("Channels marked read", 800);
+          } else {
+            _task->clearRoomUnread();
+            _task->showAlert("Rooms marked read", 800);
+          }
+        }
+        return true;
+      }
       if (c == KEY_CANCEL) { _task->gotoHomeScreen(); return true; }
       if (c == KEY_UP && _mode_sel > 0) { _mode_sel--; return true; }
       if (c == KEY_DOWN && _mode_sel < 2) { _mode_sel++; return true; }
+      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.addItem("Mark all read");
+        return true;
+      }
       if (c == KEY_ENTER) {
         if (_mode_sel == 1) {
           _phase = CHANNEL_PICK;

examples/companion_radio/ui-new/UITask.h

@@ -136,6 +136,7 @@ public:
       if (_dm_unread_table[i].count > 0 && memcmp(_dm_unread_table[i].prefix, pub_key, 4) == 0)
         { _dm_unread_table[i].count = 0; return; }
   }
+  void clearAllDMUnread() { memset(_dm_unread_table, 0, sizeof(_dm_unread_table)); }
   bool hasDisplay() const { return _display != NULL; }
   bool isButtonPressed() const;