Comprehensive review fixes: security, performance, code quality, and UI polish

Backend: Fix CORS wildcard+credentials, add secret key warning, remove raw
API keys from sync endpoint, fix N+1 queries in watcher/sync, fix
AttributeError on event_types, delete dead scheduled.py/templates.py,
add limit cap on history, re-validate server on URL/key update, apply
tracking/template config IDs in update_target.

HA Integration: Replace datetime.now() with dt_util.now(), fix notification
queue to only remove successfully sent items, use album UUID for entity
unique IDs, add shared links dirty flag and users cache hourly refresh,
deduplicate _is_quiet_hours, add HTTP timeouts, cache albums in config
flow, change iot_class to local_polling.

Frontend: Make i18n reactive via $state (remove window.location.reload),
add Modal transitions/a11y/Escape key, create ConfirmModal replacing all
confirm() calls, add error handling to all pages, replace Unicode nav
icons with MDI SVGs, add card hover effects, dashboard stat icons, global
focus-visible styles, form slide transitions, mobile responsive bottom
nav, fix password error color, add ~20 i18n keys (EN/RU).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

custom_components/immich_album_watcher/binary_sensor.py

@@ -3,7 +3,9 @@
 from __future__ import annotations
 
 import logging
-from datetime import datetime, timedelta
+from datetime import timedelta
+
+from homeassistant.util import dt as dt_util
 
 from homeassistant.components.binary_sensor import (
     BinarySensorDeviceClass,
@@ -74,7 +76,7 @@ class ImmichAlbumNewAssetsSensor(
         self._album_id = subentry.data[CONF_ALBUM_ID]
         self._album_name = subentry.data.get(CONF_ALBUM_NAME, "Unknown Album")
         self._hub_name = entry.data.get(CONF_HUB_NAME, "Immich")
-        unique_id_prefix = slugify(f"{self._hub_name}_album_{self._album_name}")
+        unique_id_prefix = slugify(f"{self._hub_name}_{self._album_id}")
         self._attr_unique_id = f"{unique_id_prefix}_new_assets"
 
     @property
@@ -93,7 +95,7 @@ class ImmichAlbumNewAssetsSensor(
 
         # Check if we're still within the reset window
         if self._album_data.last_change_time:
-            elapsed = datetime.now() - self._album_data.last_change_time
+            elapsed = dt_util.now() - self._album_data.last_change_time
             if elapsed > timedelta(seconds=NEW_ASSETS_RESET_DELAY):
                 # Auto-reset the flag
                 self.coordinator.clear_new_assets_flag()