fix(input): prevent layout shift when hiding password toggle (#30533)

Issue number: resolves #29562 

---------

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issue. -->

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## What is the current behavior?
When an input with a password toggle is given `disabled` or `readonly`,
hiding the password toggle causes a layout shift as it shrinks the
height of the input component.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->
- Password toggle is given `visibility: hidden` instead of removing it
from the DOM with `display: none` so it retains it's space but is still
hidden and still removed from the accessibility tree.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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  2. Update the BREAKING.md file with the breaking change.
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## Other information

This solution was suggested by @piotr-cz in the bug report.
<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

---------

Co-authored-by: Brandy Smith <6577830+brandyscarney@users.noreply.github.com>

core/src/components/input/input.scss

@@ -618,5 +618,5 @@
  */
 :host([disabled]) ::slotted(ion-input-password-toggle),
 :host([readonly]) ::slotted(ion-input-password-toggle) {
-  display: none;
+  visibility: hidden;
 }

core/src/components/input/test/states/input.e2e.ts

@@ -26,5 +26,69 @@ configs({ directions: ['ltr'] }).forEach(({ title, screenshot, config }) => {
       const input = page.locator('ion-input');
       await expect(input).toHaveScreenshot(screenshot(`input-disabled`));
     });
+
+    test('should maintain consistent height when password toggle is hidden on disabled input', async ({
+      page,
+    }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/29562',
+      });
+      await page.setContent(
+        `
+        <ion-input label="Password" type="password" value="password123">
+          <ion-input-password-toggle slot="end"></ion-input-password-toggle>
+        </ion-input>
+      `,
+        config
+      );
+
+      const input = page.locator('ion-input');
+
+      // Get the height when input is enabled
+      const enabledHeight = await input.boundingBox().then((box) => box?.height);
+
+      // Disable the input
+      await input.evaluate((el) => el.setAttribute('disabled', 'true'));
+      await page.waitForChanges();
+
+      // Get the height when input is disabled
+      const disabledHeight = await input.boundingBox().then((box) => box?.height);
+
+      // Verify heights are the same
+      expect(enabledHeight).toBe(disabledHeight);
+    });
+
+    test('should maintain consistent height when password toggle is hidden on readonly input', async ({
+      page,
+    }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/29562',
+      });
+      await page.setContent(
+        `
+        <ion-input label="Password" type="password" value="password123">
+          <ion-input-password-toggle slot="end"></ion-input-password-toggle>
+        </ion-input>
+      `,
+        config
+      );
+
+      const input = page.locator('ion-input');
+
+      // Get the height when input is enabled
+      const enabledHeight = await input.boundingBox().then((box) => box?.height);
+
+      // Make the input readonly
+      await input.evaluate((el) => el.setAttribute('readonly', 'true'));
+      await page.waitForChanges();
+
+      // Get the height when input is readonly
+      const readonlyHeight = await input.boundingBox().then((box) => box?.height);
+
+      // Verify heights are the same
+      expect(enabledHeight).toBe(readonlyHeight);
+    });
   });
 });