Build/Test Tools: Address visual regression test review feedback.

Add a 10 s safety timeout to the jQuery animation polling loop to prevent
a stuck animation from hanging the suite. Remove the unused `masks`-as-function
code path. Clarify comments for the Add New Plugin mask scope and the
`.error:not(#error)` CSS selector. Note in the README that the Playwright
`webServer` config auto-starts the environment.

Author: josephfusco

tests/visual-regression/README.md

@@ -6,6 +6,8 @@ screens and compare them against baseline snapshots.
 ## How to Run the Tests Locally
 
 1. Start the local environment: `npm run env:start`
+   *(The Playwright `webServer` config starts the environment automatically
+   when you run the tests, but running it first avoids the cold-start wait.)*
 2. Generate baseline snapshots: `npm run test:visual -- --update-snapshots`
 3. Make your changes.
 4. Run `npm run test:visual` — any visual differences will fail and produce

tests/visual-regression/config/screenshot.css

@@ -50,7 +50,11 @@
 	visibility: hidden !important;
 }
 
-/* Admin notices — various nags (PHP deprecation, updates, etc.). */
+/*
+ * Admin notices — various nags (PHP deprecation, updates, etc.).
+ * `.error:not(#error)` excludes the `#error` container on wp-login.php,
+ * which displays user-facing login errors and is part of the intended UI.
+ */
 .notice,
 .update-nag,
 .updated,

tests/visual-regression/specs/visual-snapshots.test.js

@@ -55,6 +55,12 @@ async function waitForPageReady( page ) {
 					resolve();
 				}
 			}, 100 );
+			// Safety valve: resolve after 10 s so a stuck animation or
+			// unresolved AJAX request doesn't hang the entire suite.
+			setTimeout( () => {
+				clearInterval( interval );
+				resolve();
+			}, 10000 );
 		} );
 	} );
 }
@@ -207,7 +213,10 @@ const pages = [
 		name: 'Add New Plugin',
 		path: '/plugin-install.php',
 		masks: [
-			// Plugin cards show external content that changes frequently.
+			// Plugin cards show external content (descriptions, ratings,
+			// download counts) that changes frequently. Masking all cards
+			// means this test only verifies the page shell — search bar,
+			// header tabs, and pagination layout.
 			'.plugin-card',
 		],
 	},
@@ -291,8 +300,6 @@ test.describe( 'Admin Visual Snapshots', () => {
 					}
 
 					screenshotOptions = { mask: locators };
-				} else if ( typeof masks === 'function' ) {
-					screenshotOptions = { mask: masks( page ) };
 				}
 
 				await expect( page ).toHaveScreenshot(