chore: stage I1 -- repo cleanup, minimal README

Working plans (docs/development, docs/design redesign notes) removed; the
two developer guides moved to docs/developer/. README cut to devices,
flashing, links and building (Wio Tracker L2 added); its feature list and
doc tables moved to docs/solo_features/README.md. RELEASE.md describes the
Solo release flow. Upstream's GitHub Pages workflow (docs.meshcore.io)
dropped, CLAUDE.md untracked, Buy Me a Coffee back in FUNDING.yml.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/companion_radio/Features.h

@@ -40,7 +40,7 @@
 // (RadioLibWrapper::armRecv()/CustomSX1262Wrapper::startPowerSaveRecv()) is
 // left in place for if a network-wide compatibility mechanism ever lands --
 // flipping this back to 1 requires solving that first, not just re-adding the
-// Settings toggle. See docs/development/roadmap.md for the full writeup.
+// Settings toggle.
 // Lives here (not MyMesh.h) so every `#if FEAT_RX_POWERSAVE` user sees the
 // same definition: an undefined macro in `#if` silently reads as 0, which
 // would split the build the day this is flipped to 1.

examples/companion_radio/ui-core/DmUnreadTable.h

@@ -4,7 +4,7 @@
 // and always read back clamped to what the ring still holds for that contact --
 // the same self-healing shape as MessageHistory::chUnread() for channels.
 //
-// Header-only UI Core model (see docs/development/ui-core.md); no drawing, no
+// Header-only UI Core model (see docs/developer/ui-core.md); no drawing, no
 // screen state.
 
 class DmUnreadTable {

examples/companion_radio/ui-core/SettingsSchema.h

@@ -1,5 +1,5 @@
 #pragma once
-// Declarative settings (docs/development/ui-core.md, step 4): one table of
+// Declarative settings (docs/developer/ui-core.md, step 4): one table of
 // NodePrefs options with their labels, value lists and side effects, so every
 // frontend renders the same settings without its own per-item code. ui-lvgl
 // draws it as switches and dropdowns, one page per Page below; ui-new still has

examples/companion_radio/ui-core/UiCore.h

@@ -1,6 +1,6 @@
 #pragma once
 // UI Core: hardware-independent UI state and logic shared by every frontend
-// (ui-new today, ui-lvgl later). See docs/development/ui-core.md.
+// (ui-new today, ui-lvgl later). See docs/developer/ui-core.md.
 //
 // The Core is MyMesh's Listener: it files incoming/outgoing messages into the
 // history, keeps the unread counters, runs the engines, and tells the frontend

examples/companion_radio/ui-core/UiCoreHost.h

@@ -4,7 +4,7 @@
 // does, and reports to the frontend through UiEventQueue. This interface is the
 // remainder -- calls that must stay synchronous with mesh processing, or whose
 // logic still lives in the frontend until its extraction step
-// (docs/development/ui-core.md). None of these may draw or block.
+// (docs/developer/ui-core.md). None of these may draw or block.
 
 class UiCoreHost {
 public:

examples/companion_radio/ui-core/UiEvents.h

@@ -2,7 +2,7 @@
 // Core → frontend events. Engines never call into the frontend (no drawing, no
 // sound, no display power); they push a tagged event here and the frontend
 // drains the queue from its own loop() and reacts in its own way (ui-new:
-// alert overlay + buzzer; ui-lvgl: a dialog). See docs/development/ui-core.md.
+// alert overlay + buzzer; ui-lvgl: a dialog). See docs/developer/ui-core.md.
 //
 // Fixed-size ring, no heap. When full the oldest event is dropped -- events are
 // hints for the view; the authoritative state stays queryable on the engines.

examples/companion_radio/ui-lvgl/UITask.cpp

@@ -95,7 +95,7 @@ static const char* waypointsFull() {
   return t;
 }
 
-// ui-lvgl skeleton (docs/development/ui-core.md, step 5): status bar, home,
+// ui-lvgl skeleton (docs/developer/ui-core.md, step 5): status bar, home,
 // conversation list, contact picker, conversation view with compose. Every
 // piece of state it shows comes from the UI Core; this file only draws it.
 
@@ -990,8 +990,7 @@ void UITask::loop() {
   prefsFlush();
   usbPoll();
 #if defined(UI_HEAP_REPORT) && defined(ESP32)
-  // -D UI_HEAP_REPORT: internal / PSRAM heap once, 20 s after boot (the
-  // framework comparison in docs/development/l2-roadmap.md).
+  // -D UI_HEAP_REPORT: internal / PSRAM heap once, 20 s after boot.
   static bool heap_done = false;
   if (!heap_done && millis() > 20000) {
     heap_done = true;

examples/companion_radio/ui-lvgl/UITask.h

@@ -1,7 +1,7 @@
 #pragma once
 // ui-lvgl: the rich (colour + touch) frontend of the UI Core. Wio Tracker L2
 // first. All application state lives in the Core (../ui-core); this class owns
-// only LVGL screens, display power and input. See docs/development/ui-core.md.
+// only LVGL screens, display power and input. See docs/developer/ui-core.md.
 
 #include <MeshCore.h>
 #include <Arduino.h>