feat!: remove the old API, ports 8081 and 8080 (step 4a)

Step 4a of docs/SECURITY_PLAN.md. Port 80 keeps the eleven HTTP routes of
ADR 0006 and the socket at /ws; everything else moved to protocol 2.

- Port 8081 (ApiRoutes) and the socket on 8080 (SocketEmitter) are gone.
  Protocol 2 owns its frame buffer and loop-task check.
- Port 80 drops every route the old web UI called: reads, edits,
  settings, scans, reboot, /shades.cfg, /discovery. HttpRoutes.cpp holds
  what stays.
- ModelSnapshot, SnapshotSlots and the read documents are gone. The item
  snapshot types stay, as ItemSnapshot, for events, MQTT and the command
  replies.
- Model edits reply only to their protocol 2 op: requestResult goes.
- The settings' toJSON writers, used only by the settings routes, go.
- The _espsomfy_rts._tcp mDNS record moves to port 80, with path=/ws.
- The memory event reports the loop-rate window it closes.
- A deleted room no longer re-publishes its retained MQTT topics.
- e2e: the heap check reads the sync's status; the sync is checked on
  its own instead of against /controller.
- README gets an API and ports section.

BREAKING CHANGE: ports 8081 and 8080 and the old HTTP routes are gone.
Home Assistant needs integration 3.0.0 or newer.

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

src/SomfyEditor.h

@@ -5,23 +5,19 @@
 #include "ProtoFrame.h"
 
 // ModelEditor on the device: an edit of the shade model handed from the web
-// server task to loop(), which applies it with the ModelEditor rules and tells
-// the clients how it went.
+// server task to loop(), which applies it with the ModelEditor rules and replies
+// to the client that sent it.
 
-// One edit on its way to loop(): the edit route and a copy of its request.
-// From an edit route its result goes to every client as requestResult; from a
-// protocol 2 edit op, as its reply.
+// One edit on its way to loop(): the protocol 2 edit op and a copy of its
+// arguments.
 struct model_edit_t {
   model_edit_type_t type = model_edit_type_t::add_room;
-  uint32_t requestId = 0;
   proto_reply_to_t replyTo;
   JsonDocument doc;
 };
 
 // One edit at a time: false when one is already waiting or running.  Any task.
 bool beginModelEdit();
-// The id the HTTP reply and the requestResult event carry.  Any task.
-uint32_t nextEditRequestId();
 // Gives up an edit that was begun but never queued.  Any task.
 void cancelModelEdit(model_edit_t *edit);
 // Begins an edit of that type: nullptr when one is already waiting or running
@@ -30,10 +26,8 @@ model_edit_t *newModelEdit(model_edit_type_t type, bool &busy);
 // Hands a begun edit to loop(); false when the queue is full, and it is given
 // up.  Any task.
 bool submitModelEdit(model_edit_t *edit);
-// Applies the edit, saves it, tells how it went and frees it.  loop() only.
+// Applies the edit, saves it, replies and frees it.  loop() only.
 void runModelEdit(model_edit_t *edit);
 // Applies the edit to the shade model and saves it.  loop() only.
 edit_result_t applyModelEdit(model_edit_t &edit);
-// Tells every client how the edit went (SomfyEvents.cpp).
-void emitRequestResult(uint32_t requestId, const edit_result_t &result);
 #endif