feat: Add festive visual effects (#2252)

<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Introduces an effects system (fireworks, ghost, hearts, shamrocks,
snow), a new `effect` action, and optional date-based loading effects,
integrated into the card with docs, schema, editor, and tests.
> 
> - **Effects System**:
> - Add `EffectsController` and `advanced-camera-card-effects` host with
lazy-loaded effect modules (`fireworks`, `ghost`, `hearts`, `shamrocks`,
`snow`).
> - New base effect component with fade-in/out; SCSS and z-index
updates.
> - **Actions**:
> - New custom action `advanced_camera_card_action: effect` with
`effect_action` (`start`|`stop`|`toggle`).
>   - Wire into `ActionFactory` and add `EffectAction` executor.
> - **Card Integration**:
> - Mount effects host in `advanced-camera-card` and expose
`getEffectsControllerAPI()` via `CardController`.
> - Loading component can trigger date-based effects (e.g., New Year
fireworks) when enabled.
> - **Configuration & Editor**:
> - Add `performance.features.card_loading_effects` (default `true`)
alongside `card_loading_indicator`.
> - Update schemas, defaults, low-performance profile (disables
effects), and editor toggles.
> - **Docs & Examples**:
>   - Document `effect` action parameters and add menu example.
>   - Update performance docs with new option.
> - **Localization & Tests**:
>   - Update i18n strings for new performance option.
> - Add comprehensive tests for effects controller, action, factory,
config defaults/profiles, and utilities.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
cffd4304fe3bd22340316f9cec53e341379b1756. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

src/components/effects/base.ts

@@ -0,0 +1,53 @@
+import { CSSResultGroup, LitElement, PropertyValues, unsafeCSS } from 'lit';
+import { property } from 'lit/decorators.js';
+import effectBaseStyle from '../../scss/effect-base.scss';
+import { forceReflow } from '../../utils/basic';
+
+export abstract class BaseEffectComponent extends LitElement {
+  @property({ type: Boolean })
+  public fadeIn = true;
+
+  protected firstUpdated(): void {
+    if (this.fadeIn) {
+      this._startFadeIn();
+    }
+  }
+
+  protected updated(changedProps: PropertyValues): void {
+    // Skip if this is the initial property setting (handled by firstUpdated).
+    if (changedProps.get('fadeIn') !== undefined) {
+      if (!this.fadeIn) {
+        this._setOpacity(1);
+      } else {
+        this._startFadeIn();
+      }
+    }
+  }
+
+  public startFadeOut(): Promise<void> {
+    return new Promise((resolve) => {
+      const handler = (ev: TransitionEvent) => {
+        if (ev.propertyName === 'opacity') {
+          this.removeEventListener('transitionend', handler);
+          resolve();
+        }
+      };
+      this.addEventListener('transitionend', handler);
+      this._setOpacity(0);
+    });
+  }
+
+  private _startFadeIn(): void {
+    this._setOpacity(0);
+    forceReflow(this);
+    this._setOpacity(1);
+  }
+
+  private _setOpacity(opacity: number): void {
+    this.style.opacity = `${opacity}`;
+  }
+
+  static get styles(): CSSResultGroup {
+    return unsafeCSS(effectBaseStyle);
+  }
+}