refactor(config): drop the androidtv media_player entity path end-to-end (t41)

The user ruling: this integration REPLACES both old integrations, so nothing may
depend on an androidtv/androidtv_remote entity anymore.

Removed:
* the setup-form field + its entity selector (CONF_ANDROIDTV_ENTITY is no longer
  offered, only read by the migration that drops it);
* the entity-derived unique_id derivation (_unique_id_from_atv_device, t29 G2)
  and, with it, every registry lookup for another integration's devices — the
  user step now sets NO unique_id at all; the protocol MAC learned during
  pairing is the identity;
* the Jellyfin auto-detect's second tier (the atv entity's friendly_name) — it
  now uses the entry name the user typed or the device name from discovery;
* the app-name and app-id tiers (media_player.app_name/app_id + the shared
  resolve_app_name chain, the Current App sensor, the sensor's state-change
  listener and its `_androidtv_state` helper) — the manager's store is the only
  source;
* the "transitional external entity" command tier in every path: `_cmd` and the
  pan-media_player service call are gone, and so is the fallback in _media_cmd,
  _remote_key_cmd, the §7 channel-digit sequence and the intent self-heal retry
  (an intent no transport served now surrenders to the truth instead of
  delegating);
* the entity-derived power signal (`_on_source_change`'s "device off clears the
  intent" check no longer watches another integration's entity; the power
  LADDER — protocol is_on → ADB wake → power switch — is unchanged).

turn_on/turn_off are native now: they send the protocol POWER key and, like the
remote entity, send nothing when the known state already matches (no superfluous
toggle). An ADB-only entry (protocol skipped) has no power write path — the
manager owns the socket and exposes no device-keyevent, which is what the old
delegation used to cover.

helpers.discover_adb_host — the one helper that derived a host from another
integration's config entry — is deleted; button.py (granted to this task) reads
the entry's own address fields instead of the entity, so the Pair ADB button
keeps working.

Present-day entries that still carry the key are unaffected (nothing reads it);
the v3 migration that drops it lands with the host unification.

Verified: 309 passed / 2 skipped, 310 / 1 with androidtvremote2, ruff clean,
drift engine exit 0 on HEAD (13 modules, 58 imports, 35 call arguments, 6
awaited HA calls) and 16 passed in the real-HA drift suite. The stub harness's
legacy service recorder became a watchdog: any HA service call from the media
player now fails the routing tests instead of being the expected outcome.

tests/test_command_routing.py

@@ -116,6 +116,7 @@ def make_player(modules, manager=None, jellyfin_entity=None, options=None):
     player._entry = entry
     player._manager = manager
     player._intent = None
+    player._intent_timer_unsub = None  # mirrors __init__ (intent self-heal)
     player._last_channel = None
     player.hass = entity_stublib.FakeHass()
     player._entity_tasks = set()
@@ -123,13 +124,16 @@ def make_player(modules, manager=None, jellyfin_entity=None, options=None):
     player.async_write_ha_state = lambda: None
     player._read = lambda eid: None
 
+    # t41: nothing may leave this integration, so an HA service call is now the
+    # failure signal rather than a supported tier. `served` stays empty unless a
+    # regression reintroduces the external-entity delegation.
     served = []
 
-    async def _cmd(service, **kwargs):
-        served.append(("legacy", service))
-        return None
+    class _RecordingServices:
+        async def async_call(self, domain, service, data=None, **kwargs):
+            served.append((domain, service))
 
-    player._cmd = _cmd
+    player.hass.services = _RecordingServices()
 
     captured_intents = []
 
@@ -248,7 +252,8 @@ class TestChannelDigits:
 
         await player._channel_entry_sequence(["7"])
 
-        assert served == [("legacy", "play_media")]  # transitional path used
+        # t41: both transports down is a no-op — no other integration is called
+        assert served == []
 
 
 class TestAppAndUrls:
@@ -346,38 +351,67 @@ class TestRemoteEntity:
         assert protocol.key_calls == []
 
 
+class TestIntentRetryWithoutATransport:
+    """t41: an intent no transport served surrenders instead of delegating."""
+
+    def _intent(self, **overrides):
+        from types import SimpleNamespace
+
+        intent = SimpleNamespace(
+            target_state="playing",
+            command="media_play",
+            created_at=0.0,
+            prior_state=None,
+            retry_count=0,
+            via_adb=False,
+            via_protocol=False,
+            adb_command=None,
+            protocol_key=None,
+        )
+        for key, value in overrides.items():
+            setattr(intent, key, value)
+        return intent
+
+    async def test_unserved_intent_surrenders_without_a_service_call(self, modules):
+        player, served, _intents = make_player(modules)
+        player.async_write_ha_state = lambda: None
+        player._intent = self._intent()
+
+        player._on_intent_timeout(0.0)  # async_call_later passes the timestamp
+
+        assert player._intent is None  # surrendered to the truth
+        assert served == []  # and nothing left this integration
+
+    async def test_protocol_served_intent_still_retries_over_the_protocol(self, modules):
+        player, served, _intents = make_player(modules)
+        player.async_write_ha_state = lambda: None
+        protocol = player._manager._protocol
+        player._intent = self._intent(
+            via_protocol=True, protocol_key="KEYCODE_MEDIA_PLAY"
+        )
+
+        player._on_intent_timeout(0.0)  # async_call_later passes the timestamp
+        await asyncio.sleep(0.05)
+
+        assert protocol.key_calls == [("KEYCODE_MEDIA_PLAY", "SHORT")]
+        assert served == []
+
+
 class TestAppFallback:
-    async def test_app_id_prefers_the_androidtv_entity(self, modules):
+    """t41: the app identity comes from OUR transports' store only."""
+
+    async def test_app_id_comes_from_the_manager_store(self, modules):
         player, _s, _i = make_player(modules)
-        player._androidtv_entity = "media_player.atv"
-        from types import SimpleNamespace as FakeState
-
-        state = FakeState(attributes={"app_id": "com.plex.hdx", "app_name": "Plex"})
-        states = FakeState(states=FakeState(
-            get=lambda eid: state if eid == "media_player.atv" else None
-        ))
-        player.hass = states
-        player._read = lambda eid: state if eid == "media_player.atv" else None
-
-        assert player.app_id == "com.plex.hdx"
-        assert player.app_name == "Plex"
-
-    async def test_app_falls_back_to_protocol_current_app(self, modules):
-        player, _s, _i = make_player(modules)
-        player._androidtv_entity = ""  # standalone setup (P3-1)
-        player._manager._on_current_app("com.netflix.ninja")
+        player._manager._on_current_app("com.plex.hdx")
         await asyncio.sleep(0.05)  # drain the call_soon_threadsafe push
 
-        assert player.app_id == "com.netflix.ninja"
-        assert player.app_name == "com.netflix.ninja"  # package is truth; map later
+        assert player.app_id == "com.plex.hdx"
+        assert player.app_name == "com.plex.hdx"  # package is truth; map later
 
-    async def test_app_unavailable_entity_falls_back(self, modules):
+    async def test_app_follows_the_latest_protocol_push(self, modules):
         player, _s, _i = make_player(modules)
-        player._androidtv_entity = "media_player.atv"
-        from types import SimpleNamespace as FakeState
-
-        player.hass = FakeState(states=FakeState(get=lambda eid: None))  # entity gone
-        player._read = lambda eid: None
+        player._manager._on_current_app("com.netflix.ninja")
+        await asyncio.sleep(0.05)
         player._manager._on_current_app("com.google.android.youtube.tv")
         await asyncio.sleep(0.05)
 
@@ -393,7 +427,6 @@ def _ladder_player(modules, foreground=None, audio=None):
         manager.store.set("foreground", foreground)
     if audio:
         manager.store.set("audio_playback", audio)
-    player._androidtv_entity = ""
     player._read = lambda eid: None
     return player, manager
 
@@ -411,7 +444,6 @@ class TestForegroundLadderTier:
             manager.store.set("foreground", foreground)
         if audio:
             manager.store.set("audio_playback", audio)
-        player._androidtv_entity = ""
         player._read = lambda eid: None
         return player, manager
 
@@ -1187,12 +1219,16 @@ def make_manager_with(*, poller=None, protocol=None):
     )
 
 
-def make_app_sensor(modules, manager, entry, *, atv_state=None):
-    """A Current App sensor over the given manager/entry (t40)."""
+def make_app_sensor(modules, manager, entry):
+    """A Current App sensor over the given manager/entry (t40).
+
+    t41: the sensor reads the manager's store and nothing else, so the harness
+    hands it a hass whose state machine is empty — a value here can only come
+    from our own transports.
+    """
     from types import SimpleNamespace
 
-    states = {"media_player.atv": atv_state} if atv_state is not None else {}
-    hass = SimpleNamespace(states=SimpleNamespace(get=states.get))
+    hass = SimpleNamespace(states=SimpleNamespace(get=lambda entity_id: None))
     return modules["sensor"].NvidiaShieldCurrentAppSensor(hass, entry)
 
 
@@ -1232,20 +1268,6 @@ class TestCurrentAppSensorFriendlyName:
         assert sensor.native_value == "Netflix"
         assert sensor.extra_state_attributes["app_id"] == "com.netflix.ninja"
 
-    def test_androidtv_entity_tier_serves_when_no_map_or_label(self, modules):
-        from types import SimpleNamespace
-
-        player, _served, _intents = make_player(modules)
-        player._entry.data["androidtv_entity"] = "media_player.atv"
-        atv_state = SimpleNamespace(
-            attributes={"app_id": "ar.tvplayer.tv", "app_name": "ATV Tivi"}
-        )
-        sensor = make_app_sensor(modules, player._manager, player._entry, atv_state=atv_state)
-
-        player._manager._on_current_app("ar.tvplayer.tv")
-
-        assert sensor.native_value == "ATV Tivi"
-
     def test_recent_apps_fallback_resolves_through_the_label_tier(self, modules):
         player, _served, _intents = make_player(modules)
         manager = player._manager
@@ -1271,7 +1293,6 @@ class TestCurrentAppSensorFriendlyName:
         """One chain, two entities — they cannot disagree about the app name."""
         player, _served, _intents = make_player(modules)
         player._entry.options["app_name_map"] = {"ar.tvplayer.tv": "TiviMate"}
-        player._androidtv_entity = ""  # standalone, like the unit harness
         sensor = self._sensor(modules, player)
 
         player._manager._on_current_app("ar.tvplayer.tv")