Fix Abilities Explorer page heading

[ekamran]

What?

Fixes the Abilities Explorer admin page heading so it matches the feature name used everywhere else in the UI.

The page title and Tools menu already use “Abilities Explorer”, but the page heading showed “Ability Explorer”.

Why?

The mismatch is visible in the WordPress admin and makes the experiment name inconsistent across the same screen.

How?

• Updates the Abilities Explorer page <h1> from “Ability Explorer” to “Abilities Explorer”.
• Updates the existing PHP integration assertion.
• Adds E2E coverage for the visible page heading.

Testing Instructions

Automated checks run locally:

npm run build
npm run lint:js
npm run typecheck
npm run test:php
npm run lint:php
npm run lint:php:stan
npm run test:e2e -- tests/e2e/specs/experiments/abilities-explorer.spec.js

Focused Abilities Explorer E2E passed:

npm run test:e2e -- tests/e2e/specs/experiments/abilities-explorer.spec.js

Full E2E was also run:

npm run test:e2e

The Abilities Explorer tests passed in the full run. The full suite had unrelated failures outside this patch area.

Screenshots/Screencast

Before

The page heading showed “Ability Explorer”, while the menu and browser title showed “Abilities Explorer”.

After

The page heading now matches the menu and browser title.

Use of AI Tools

AI assistance: Yes
Tool(s): ChatGPT / Codex
Used for: Repository review, reproduction planning, implementation guidance, test updates, and local verification. I reviewed the changes, tested the behavior locally, and take responsibility for the final submission.

[github-actions]

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Co-authored-by: ekamran <ekamran@git.wordpress.org>

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.40%. Comparing base (a3d7944) to head (aa65f59).
⚠️ Report is 3 commits behind head on develop.

Additional details and impacted files

@@              Coverage Diff              @@
##             develop     #585      +/-   ##
=============================================
+ Coverage      71.41%   72.40%   +0.99%     
- Complexity      1158     1162       +4     
=============================================
  Files             67       68       +1     
  Lines           5586     5596      +10     
=============================================
+ Hits            3989     4052      +63     
+ Misses          1597     1544      -53     

Flag	Coverage Δ
unit	72.40% <100.00%> (+0.99%)	⬆️

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