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/SupportPage.svelte

@@ -0,0 +1,50 @@
+<script>
+	import {onMount} from "svelte";
+	import {api, config, diagnostics, strings, urls} from "../js/stores";
+	import Page from "./Page.svelte";
+	import Notifications from "./Notifications.svelte";
+
+	export let name = "support";
+	export let title = $strings.support_tab_title;
+
+	onMount( async () => {
+		const json = await api.get( "diagnostics", {} );
+
+		if ( json.hasOwnProperty( "diagnostics" ) ) {
+			$config.diagnostics = json.diagnostics;
+		}
+	} );
+</script>
+
+<Page {name} on:routeEvent>
+	<Notifications tab={name}/>
+	{#if title}
+		<h2 class="page-title">{title}</h2>
+	{/if}
+	<div class="support-page wrapper">
+
+		<slot name="header"/>
+
+		<div class="columns">
+			<div class="support-form">
+				<slot name="content">
+					<div class="lite-support">
+						<p>{@html $strings.no_support}</p>
+						<p>{@html $strings.community_support}</p>
+						<p>{@html $strings.upgrade_for_support}</p>
+						<p>{@html $strings.report_a_bug}</p>
+					</div>
+				</slot>
+
+				<div class="diagnostic-info">
+					<hr>
+					<h2 class="page-title">{$strings.diagnostic_info_title}</h2>
+					<pre>{$diagnostics}</pre>
+					<a href={$urls.download_diagnostics} class="button btn-md btn-outline">{$strings.download_diagnostics}</a>
+				</div>
+			</div>
+
+			<slot name="footer"/>
+		</div>
+	</div>
+</Page>