Revert #82 (Modern Web Guidance rung-3) and re-sync mirrors

#82 added a "Web tasks: rung 3 lookup" section to the always-on ponytail
SKILL.md, about an external `modern-web` CLI most users won't have installed.
It's optional bloat in the always-on ruleset, and it broke CI by leaving the
.openclaw mirror stale.

Reverts the section from skills/ponytail/SKILL.md, the README callout, and
examples/web-platform-lookup.md, then regenerates the .openclaw mirror and
removes the Spanish callout that #174 had mirrored. Suite green (56/56).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

examples/web-platform-lookup.md

@@ -1,64 +0,0 @@
-# Web Platform Lookup
-
-**Task:** "Add a modal dialog that closes when you click the backdrop."
-
-Rung 3 of the ladder is "native platform feature covers it?" On web work the
-trap is that the agent forgets what the platform already does and reaches for a
-library. When ponytail has [Modern Web Guidance](https://github.com/GoogleChrome/modern-web-guidance)
-on hand, rung 3 gets a lookup: `modern-web search "modal dialog light dismiss"`.
-
-## Without Ponytail
-
-```bash
-npm install @radix-ui/react-dialog
-```
-
-```jsx
-import * as Dialog from "@radix-ui/react-dialog";
-
-export default function Modal({ open, onOpenChange, children }) {
-  return (
-    <Dialog.Root open={open} onOpenChange={onOpenChange}>
-      <Dialog.Portal>
-        <Dialog.Overlay className="overlay" />
-        <Dialog.Content className="content">
-          {children}
-          <Dialog.Close className="close">×</Dialog.Close>
-        </Dialog.Content>
-      </Dialog.Portal>
-    </Dialog.Root>
-  );
-}
-```
-
-A dependency, a portal, an overlay node, and controlled open state, to put a
-box on top with a backdrop.
-
-## With Ponytail
-
-`modern-web search "modal dialog light dismiss"` →
-`modern-web retrieve light-dismiss-a-dialog`. The platform has it:
-
-```html
-<!-- ponytail: <dialog> + closedby, browser does the backdrop, focus trap, and Esc -->
-<dialog closedby="any">
-  <p>...</p>
-</dialog>
-```
-
-```js
-document.querySelector("dialog").showModal();
-```
-
-**1 dependency + portal/overlay machinery → 0 dependencies + a `<dialog>`.**
-The `::backdrop` is free, focus is trapped and restored for you, `Esc` closes
-it, and `closedby="any"` adds click-outside dismissal. The browser team did the
-work.
-
-## The point
-
-MWG suggests the cutting edge, ponytail keeps only the rung that holds. The
-lookup found `light-dismiss-a-dialog`; the ladder took it because it deletes a
-dependency. The same search would have offered scroll-driven animations and
-view transitions for other tasks, and the ladder would have skipped them when
-the task didn't need them. Lookup, not license.