refactor: Centralize template render type assertion (#2538)

src/card-controller/actions/actions-manager.ts

@@ -187,15 +187,14 @@ export class ActionsManager implements ActionsExecutor {
     triggerData?: TriggerData,
   ): ActionPrepareCallback {
     // Render against the state (incl. HASS) as it is *when the action runs* --
-    // fixed trigger context, fresh card/HASS state per step. The one cast lives
-    // here as renderRecursively returns `unknown`.
+    // fixed trigger context, fresh card/HASS state per step.
     return <T>(value: T): T => {
       const hass = this._api.getHASSManager().getHASS();
       return hass
-        ? (renderer.renderRecursively(hass, value, {
+        ? renderer.renderRecursivelyAsType(hass, value, {
             conditionState: this._api.getConditionStateManager().getState(),
             triggerData,
-          }) as T)
+          })
         : value;
     };
   }

src/card-controller/templates/index.ts

@@ -31,6 +31,17 @@ export class TemplateRenderer {
     );
   };
 
+  // Structure-preserving variant of `renderRecursively`: arrays, records, and
+  // primitives keep their shape (only string leaves are rendered), so the
+  // caller's type is asserted back unchanged. Callers whose template renders to
+  // a *different* type than its input (e.g. a string that yields a boolean)
+  // must use `renderRecursively` and narrow the `unknown` result at runtime.
+  public renderRecursivelyAsType = <T>(
+    hass: HomeAssistant,
+    data: T,
+    options?: TemplateRenderOptions,
+  ): T => this.renderRecursively(hass, data, options) as T;
+
   private _generateTemplateContext(
     options?: TemplateRenderOptions,
   ): TemplateContext | undefined {

src/components/elements.ts

@@ -136,9 +136,13 @@ export class AdvancedCameraCardElementsCore extends LitElement {
       return;
     }
 
-    const elements = this._templateRenderer.renderRecursively(this.hass, this.elements, {
-      conditionState: this.conditionStateManager?.getState(),
-    }) as PictureElements | undefined;
+    const elements = this._templateRenderer.renderRecursivelyAsType(
+      this.hass,
+      this.elements,
+      {
+        conditionState: this.conditionStateManager?.getState(),
+      },
+    );
 
     // Condition state changes won't change the actual rendered config unless
     // `elements` has a template, which is more likely does not. Avoid updating