Multiple identities via config subentries + regenerate + editable name

Refactor from one-entry-one-identity to a hub config entry (shared RNS stack)
plus config subentries of type "identity", each an independent LXMF identity
with its own LXMRouter, address, device and entities. This is required because
LXMRouter allows only one delivery identity per instance.

- ReticulumStack: owns the single process-wide RNS instance, peer discovery and
  interface telemetry (hub device).
- IdentityManager: one per subentry, its own LXMRouter/identity/destination and
  delivery callback (identity device). Signal handlers suppressed and atexit
  handlers tamed for each router too.
- Config subentry flow (add / reconfigure identity); a first identity is seeded
  on stack creation. Editable announce display name = subentry title.
- Per-identity "Regenerate identity" button: new address + re-announce
  (clears the router's single delivery destination first).
- Services and events gain an "identity" field to target/distinguish identities.
- Per-identity assist bridge, greeting-when-assist-off, allow-list, notify,
  announce/sync buttons, message counters; hub-level connectivity/telemetry/peers.

Verified against current HA config_entries/entity_platform/selector and RNS/LXMF
sources. Docs and en/ru translations updated.

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

custom_components/reticulum/notify.py

@@ -1,8 +1,8 @@
-"""Notify platform for Reticulum.
+"""Notify platform for Reticulum (per identity).
 
-Exposes a ``notify`` entity that sends an LXMF message to the configured
-default recipient. For arbitrary destinations use the ``reticulum.send_message``
-service instead.
+Each identity exposes a ``notify`` entity that sends an LXMF message from that
+identity to its configured default recipient. For arbitrary destinations use
+the ``reticulum.send_message`` service.
 """
 
 from __future__ import annotations
@@ -13,9 +13,15 @@ from homeassistant.core import HomeAssistant
 from homeassistant.exceptions import ServiceValidationError
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 
-from .const import CONF_DEFAULT_RECIPIENT, CONF_DELIVERY_METHOD, DEFAULT_DELIVERY_METHOD, DOMAIN
-from .entity import ReticulumEntity
-from .reticulum_client import ReticulumError, ReticulumManager
+from .const import (
+    CONF_DEFAULT_RECIPIENT,
+    CONF_DELIVERY_METHOD,
+    DEFAULT_DELIVERY_METHOD,
+    DOMAIN,
+    SUBENTRY_TYPE_IDENTITY,
+)
+from .entity import ReticulumIdentityEntity
+from .reticulum_client import ReticulumError
 
 
 async def async_setup_entry(
@@ -23,32 +29,42 @@ async def async_setup_entry(
     entry: ConfigEntry,
     async_add_entities: AddEntitiesCallback,
 ) -> None:
-    """Set up the Reticulum notify entity."""
-    manager: ReticulumManager = hass.data[DOMAIN][entry.entry_id].manager
-    async_add_entities([ReticulumNotify(manager, entry)])
+    """Set up per-identity notify entities."""
+    runtime = hass.data[DOMAIN][entry.entry_id]
+    for subentry in entry.subentries.values():
+        if subentry.subentry_type != SUBENTRY_TYPE_IDENTITY:
+            continue
+        manager = runtime.identities.get(subentry.subentry_id)
+        if manager is None:
+            continue
+        async_add_entities(
+            [ReticulumNotify(manager, entry, subentry)],
+            config_subentry_id=subentry.subentry_id,
+        )
 
 
-class ReticulumNotify(ReticulumEntity, NotifyEntity):
-    """Send LXMF messages to the default recipient."""
+class ReticulumNotify(ReticulumIdentityEntity, NotifyEntity):
+    """Send LXMF messages from this identity to its default recipient."""
 
     _attr_translation_key = "message"
     _attr_icon = "mdi:message-fast"
     _attr_supported_features = NotifyEntityFeature.TITLE
 
-    def __init__(self, manager: ReticulumManager, entry: ConfigEntry) -> None:
-        super().__init__(manager, entry.entry_id)
-        self._entry = entry
-        self._attr_unique_id = f"{entry.entry_id}_notify"
+    def __init__(self, manager, entry, subentry) -> None:
+        super().__init__(manager, entry, subentry)
+        self._attr_unique_id = f"{subentry.subentry_id}_notify"
 
     async def async_send_message(self, message: str, title: str | None = None) -> None:
-        recipient = self._entry.options.get(CONF_DEFAULT_RECIPIENT)
+        recipient = self._subentry.data.get(CONF_DEFAULT_RECIPIENT)
         if not recipient:
             raise ServiceValidationError(
-                "No default recipient configured. Set one in the Reticulum "
-                "integration options, or use the reticulum.send_message service "
+                "No default recipient configured for this identity. Set one in "
+                "the identity's options, or use the reticulum.send_message service "
                 "with an explicit destination."
             )
-        method = self._entry.options.get(CONF_DELIVERY_METHOD, DEFAULT_DELIVERY_METHOD)
+        method = self._subentry.data.get(
+            CONF_DELIVERY_METHOD, DEFAULT_DELIVERY_METHOD
+        )
         try:
             await self._manager.async_send_message(
                 recipient, message, title=title or "", method=method