feat(theme): consolidate interactive cursors into one base layer

[anilsoylu]

What

The theme has no base cursor layer. cursor: pointer is written by hand in eight places in theme/style.css, once per control, and anything the author forgets keeps the arrow. Text is worse: without a body default, every paragraph, heading and code block hands the reader an I-beam, so a docs page reads like one long text field.

This adds the base layer next to the existing element defaults and drops the per-component declarations it now covers.

a,
button,
summary,
[role="button"],
input[type="button"],
input[type="checkbox"],
input[type="radio"],
input[type="submit"] {
	cursor: pointer;
}

input,
textarea,
[contenteditable="true"] {
	cursor: text;
}

cursor: default goes into the existing body rule, and touch-action: manipulation sits next to the -webkit-tap-highlight-color rule that is already there. That one kills the 300ms double-tap-zoom delay before a control activates on touch.

summary is in the pointer list because raw HTML passes through the Markdown renderer (src/markdown.js), so a page author writing <details><summary> gets a real disclosure widget in .entry-content.

Removed as redundant

.header-button, .menu-toggle, .command-search-close, .sidebar-collapse-toggle, .sidebar-search-clear, .docs-nav-toggle, .copy-code, and the cursor line on .comment-form .submit, .post-password-form input[type="submit"]. Each one is a <button> in theme/inc/blocks.php or theme/assets/js/docs.js, so the base rule reaches all of them.

Kept: .drawer-scrim, which is a <div> the base layer cannot reach, and every cursor: default / not-allowed state override, including .docs-nav.is-filtering .docs-nav-toggle.

Scope

theme/style.css only. I left the eleven cursor: pointer declarations in plugins/docspress-blocks/ alone. DocsPress Blocks ships as its own installable plugin and its stylesheets carry literal fallbacks for every --dp-* token, so they are written to survive under another theme. No UA stylesheet gives <button> a pointer, so deleting those would regress every copy button and tab the moment the plugin runs without this theme.

add_editor_style( 'style.css' ) in theme/functions.php already loads the theme stylesheet into the editor canvas, so the base layer applies there too.

A note on checkbox and radio

They are in the pointer list on purpose. Without them, the later input, textarea rule would put an I-beam on WordPress core's comment cookie-consent checkbox, which this theme already styles at .comment-form-cookies-consent label. The attribute selectors outrank the bare input, so the cascade resolves without extra ordering rules.

Verification

New test in test/block-theme.test.js pins the four base rules, asserts the five deduplicated components no longer declare their own pointer, and guards the two intentional exceptions so a later refactor cannot quietly flatten them.

• npx vitest run test/block-theme.test.js -t "base layer" fails against unpatched style.css, passes with the change.
• npm test: 132 passed.
• npx eslint .: clean.