feat(config)!: migrate entries to v3 — one address, no androidtv key (t41)

ENTRY_VERSION = 3, declared once in const.py and reused as the flow's VERSION so
the stored shape and the migration cannot drift.

v2 → v3 mirrors the two shape changes:
* the duplicated address fields collapse into CONF_HOST — the protocol host
  wins, else the ADB host (both name the same Shield), reading options first and
  data second so a hand-written seed is covered too;
* the androidtv-entity key is dropped from data AND options with a logged note
  naming the dropped entity (the old value would only mislead now that nothing
  reads it).

A v1 entry still travels the whole way in one call (the v1→v2 protocol defaults
are applied, then the v3 collapse). Downgrades (version > 3) are rejected so HA
can offer a rollback, and the current version is a no-op.

Existing entries carrying the entity key keep working until the migration runs:
nothing reads it anymore (the c1 commit), which is exactly why the migration can
be a plain removal.

Test note: my first version of the version-parity pin called a bare
entity_stublib.install() and leaked the shallow stub set into the entity-module
loader of later tests (STATE_PAUSED/entity_available import failures). It now
uses the file's scoped harness, like every other test there.

Verified: 316 passed / 2 skipped, 317 / 1 with androidtvremote2, ruff clean,
drift engine exit 0 on HEAD (36 call arguments — one more awaited/checked call).

custom_components/nvidia_shield/__init__.py

@@ -24,11 +24,14 @@ from .const import (
     CONF_ADB_ENABLED,
     CONF_ADB_HOST,
     CONF_ADB_PORT,
+    CONF_ANDROIDTV_ENTITY,
     CONF_HOST,
     CONF_PROTOCOL_ENABLED,
+    CONF_PROTOCOL_HOST,
     DEFAULT_ADB_PORT,
     DEFAULT_NAME,
     DOMAIN,
+    ENTRY_VERSION,
     SERVICE_ADB_COMMAND,
 )
 from .helpers import (
@@ -206,26 +209,62 @@ async def _build_protocol_settings(hass: HomeAssistant, entry: ConfigEntry):
 
 
 async def async_migrate_entry(hass: HomeAssistant, config_entry: ConfigEntry) -> bool:
-    """Migrate v1 entries to v2 (adds the remote-protocol fields).
+    """Migrate an older config entry to the current version.
 
-    ADB options carry over untouched; the ADB-host discovery fallback keeps
-    serving as the protocol host until pairing populates it. Downgrades
-    (version > 2) are rejected so HA offers a rollback.
+    v1 → v2 added the remote-protocol fields (ADB options carried over
+    untouched). v2 → v3 (t41) mirrors the two changes in the stored shape:
+
+    * the duplicated address fields collapse into the single CONF_HOST — the
+      protocol host wins, else the ADB host, since both name the same Shield;
+    * the androidtv-entity key goes. This integration owns the whole stack now:
+      the entity it used to configure is neither a state source nor an app-name
+      or power tier, so keeping the value would only mislead.
+
+    Downgrades (version > ENTRY_VERSION) are rejected so HA offers a rollback.
     """
-    if config_entry.version > 2:
+    if config_entry.version > ENTRY_VERSION:
         return False
+    if config_entry.version >= ENTRY_VERSION:
+        return True
+
+    options = {**config_entry.options}
+    data = {**config_entry.data}
+
     if config_entry.version < 2:
-        options = {**config_entry.options}
         options.setdefault(CONF_PROTOCOL_ENABLED, False)
-        # t41: the entry's address is the single CONF_HOST field; a v1 entry
-        # carried it under the legacy adb_host key.
-        if not options.get(CONF_HOST):
-            options[CONF_HOST] = options.get(CONF_ADB_HOST) or ""
-        hass.config_entries.async_update_entry(
-            config_entry, options=options, version=2
+
+    if not options.get(CONF_HOST):
+        options[CONF_HOST] = (
+            options.get(CONF_PROTOCOL_HOST)
+            or options.get(CONF_ADB_HOST)
+            or data.get(CONF_PROTOCOL_HOST)
+            or data.get(CONF_ADB_HOST)
+            or ""
         )
+
+    dropped_entity = options.pop(CONF_ANDROIDTV_ENTITY, None)
+    dropped_entity = data.pop(CONF_ANDROIDTV_ENTITY, None) or dropped_entity
+    for legacy_key in (CONF_PROTOCOL_HOST, CONF_ADB_HOST):
+        options.pop(legacy_key, None)
+        data.pop(legacy_key, None)
+
+    hass.config_entries.async_update_entry(
+        config_entry, data=data, options=options, version=ENTRY_VERSION
+    )
+    if dropped_entity:
         _LOGGER.info(
-            "Migrated %s config entry to version 2", config_entry.title
+            "%s: config entry migrated to version %d — dropped the androidtv "
+            "entity %s (this integration reads the Shield directly; the entry "
+            "needs no external media_player)",
+            config_entry.title,
+            ENTRY_VERSION,
+            dropped_entity,
+        )
+    else:
+        _LOGGER.info(
+            "Migrated %s config entry to version %d",
+            config_entry.title,
+            ENTRY_VERSION,
         )
     return True