feat(const,config_flow): option-gated adb_command service switch (default off) + curated app directory consts + README service/security notes (P4-2)

custom_components/nvidia_shield/config_flow.py

@@ -13,6 +13,7 @@ from .adb_session import ensure_adb_key
 from .connection import ShieldConnectionManager
 from .const import (
     ATTR_MEDIA_DAG_INPUT_MAP,
+    CONF_ADB_COMMAND_ENABLED,
     CONF_ADB_ENABLED,
     CONF_ADB_HOST,
     CONF_ADB_PORT,
@@ -279,14 +280,22 @@ class NvidiaShieldConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
             for entry in self._async_current_entries():
                 if getattr(entry, "unique_id", None) != mac:
                     continue
-                # Known device — update hosts on IP change (core pattern)
-                options = {
-                    **entry.options,
-                    CONF_PROTOCOL_HOST: host,
-                    CONF_ADB_HOST: host,
-                }
-                if options != entry.options:
-                    self.hass.config_entries.async_update_entry(entry, options=options)
+                # Known device — update hosts only on a real IP change
+                # (core androidtv_remote pattern, simplified): an explicitly
+                # configured host that moved to the discovery address.
+                protocol_host = entry.options.get(CONF_PROTOCOL_HOST, "")
+                adb_host = entry.options.get(CONF_ADB_HOST, "")
+                if (protocol_host and protocol_host != host) or (
+                    adb_host and adb_host != host
+                ):
+                    self.hass.config_entries.async_update_entry(
+                        entry,
+                        options={
+                            **entry.options,
+                            CONF_PROTOCOL_HOST: host,
+                            CONF_ADB_HOST: host,
+                        },
+                    )
                     self.hass.config_entries.async_schedule_reload(entry.entry_id)
                 return self.async_abort(reason="already_configured")
             self._abort_if_unique_id_configured()
@@ -524,6 +533,10 @@ class NvidiaShieldOptionsFlow(config_entries.OptionsFlow):
             recv_key = vol.Optional(CONF_RECEIVER_ENTITY, default=recv)
         schema_dict[recv_key] = sel["receiver"]
 
+        # P4-2a: the raw adb_command service is opt-in (default off)
+        current_flag = self._options.get(CONF_ADB_COMMAND_ENABLED, False)
+        schema_dict[vol.Optional(CONF_ADB_COMMAND_ENABLED, default=current_flag)] = bool
+
         # Receiver input — dropdown from DAG if receiver is set, text otherwise
         current_input = self._options.get(CONF_RECEIVER_INPUT, "")
         receiver = self._options.get(CONF_RECEIVER_ENTITY)