feat: add S3-compatible storage provider (MinIO, Ceph, R2, etc.)

Adds a new 'S3-Compatible Storage' provider that works with any
S3-API-compatible object storage service, including MinIO, Ceph,
Cloudflare R2, Backblaze B2, and others.

Changes:
- New provider class: classes/providers/storage/s3-compatible-provider.php
  - Provider key: s3compatible
  - Reads user-configured endpoint URL from settings
  - Uses path-style URL access (required by most S3-compatible services)
  - Supports credentials via AS3CF_S3COMPAT_ACCESS_KEY_ID /
    AS3CF_S3COMPAT_SECRET_ACCESS_KEY wp-config.php constants
  - Disables AWS-specific features (Block Public Access, Object Ownership)
- New provider SVG icons (s3compatible.svg, -link.svg, -round.svg)
- Registered provider in main plugin class with endpoint setting support
- Updated StorageProviderSubPage to show endpoint URL input for S3-compatible
- Built pro settings bundle with rollup (Svelte 4.2.19)
- Added package.json and updated rollup.config.mjs for pro-only builds

ui/components/Pages.svelte

@@ -0,0 +1,38 @@
+<script>
+	import Router from "svelte-spa-router";
+	import {push} from "svelte-spa-router";
+	import {pages, routes} from "../js/routes";
+	import Nav from "./Nav.svelte";
+
+	// These components can be overridden.
+	export let nav = Nav;
+
+	const classes = $$props.class ? $$props.class : "";
+
+	/**
+	 * Handles events published by the router.
+	 *
+	 * This handler gives pages a chance to put their hand up and
+	 * provide a new route to be navigated to in response
+	 * to some event.
+	 * e.g. settings saved resulting in a question being asked.
+	 *
+	 * @param {Object} event
+	 */
+	function handleRouteEvent( event ) {
+		const route = pages.handleRouteEvent( event.detail );
+
+		if ( route ) {
+			push( route );
+		}
+	}
+</script>
+
+<svelte:component this={nav}/>
+
+<div class="wpome-wrapper {classes}">
+	<Router routes={$routes} on:routeEvent={handleRouteEvent}/>
+	<slot>
+		<!-- EXTRA CONTENT GOES HERE -->
+	</slot>
+</div>