test: Add a test harness for the built card (#2653)

Mounts the card from `dist/` the way Home Assistant does, by URL with a
HACS tag, and asserts the entry stays a facade, that no chunk imports
it, that the browser is served the file unmodified, and that the card
starts up and fetches a language chunk lazily.

Runs in Chromium, Firefox and WebKit, so a change of bundler or minifier
is checked against every engine.

src/action-handler-directive.ts

@@ -6,6 +6,7 @@ import {
   type DirectiveParameters,
 } from 'lit/directive.js';
 
+import { ACTION_HANDLER_HOLD_SECONDS } from './const.js';
 import { fireHASSEvent } from './ha/fire-hass-event.js';
 import type { ActionHandlerDetail, ActionHandlerOptions } from './ha/types.js';
 import { stopEventFromActivatingCardWideActions } from './utils/action.js';
@@ -24,9 +25,6 @@ interface AdvancedCameraCardActionHandlerOptions extends ActionHandlerOptions {
   allowPropagation?: boolean;
 }
 
-// How long a press must last to count as a hold rather than a tap.
-export const ACTION_HANDLER_HOLD_SECONDS = 0.4;
-
 class ActionHandler extends HTMLElement implements ActionHandlerInterface {
   public holdTime = ACTION_HANDLER_HOLD_SECONDS;
 

src/const.ts

@@ -15,6 +15,13 @@ export const TROUBLESHOOTING_LEGACY_RESOURCE_URL =
 export const TROUBLESHOOTING_MEDIA_URL =
   `${TROUBLESHOOTING_URL}?id=media-unavailable` as const;
 
+// ===========================================================================
+// Interaction Constants
+// ===========================================================================
+
+// How long a press must last to count as a hold rather than a tap.
+export const ACTION_HANDLER_HOLD_SECONDS = 0.4;
+
 // ===========================================================================
 // Media Constants
 // ===========================================================================