fix: move ESM provider wrapper from plugin to CDN

Move the ESM provider wrapper (jetpack-ai-provider-esm.mjs) from
Jetpack plugin files to the CDN build in calypso. This eliminates
the dependency on local plugin files for the provider URL, which
breaks on Simple sites where plugin files don't exist on disk.

- Delete local jetpack-ai-provider-esm.mjs
- Add AI_SIDEBAR_PROVIDER_URL constant pointing to CDN
- Update register_provider() to use CDN URL without ?ver= param
  (wrapper reads from window global at import time, always in sync)
- Update test assertions to match new URL

Author: kat3samsin

projects/plugins/jetpack/extensions/plugins/ai-assistant-plugin/ai-sidebar/class-jetpack-ai-sidebar.php

@@ -22,6 +22,7 @@
 const AI_SIDEBAR_JS_URL          = 'https://' . AM_ASSET_BASE_PATH . 'jetpack-ai-sidebar.min.js';
 const AI_SIDEBAR_CSS_URL         = 'https://' . AM_ASSET_BASE_PATH . 'jetpack-ai-sidebar.css';
 const AI_SIDEBAR_RTL_CSS_URL     = 'https://' . AM_ASSET_BASE_PATH . 'jetpack-ai-sidebar.rtl.css';
+const AI_SIDEBAR_PROVIDER_URL    = 'https://' . AM_ASSET_BASE_PATH . 'jetpack-ai-sidebar.provider.mjs';
 
 /**
  * Handles loading the Agents Manager from CDN and registering the
@@ -383,10 +384,11 @@ public static function register_provider( array $providers ): array {
 			$version
 		);
 
-		// Register as AM provider. When Big Sky is also present, AM merges
-		// both providers — abilities, suggestions, and components are combined.
-		$esm_url     = plugins_url( '_inc/blocks/ai-sidebar/jetpack-ai-provider-esm.mjs', JETPACK__PLUGIN_FILE );
-		$providers[] = $esm_url . '?ver=' . $version;
+		// Register as AM provider via CDN-hosted ESM wrapper.
+		// AM dynamically imports this module to merge tools, suggestions, and components.
+		// No ?ver= needed — the wrapper re-exports from window.__JetpackAIProvider
+		// at import time, so its behavior always matches the loaded IIFE bundle.
+		$providers[] = AI_SIDEBAR_PROVIDER_URL;
 
 		return $providers;
 	}

projects/plugins/jetpack/extensions/plugins/ai-assistant-plugin/ai-sidebar/jetpack-ai-provider-esm.mjs

@@ -281,7 +281,7 @@ public function test_register_provider_adds_url_and_enqueues() {
 		$providers = Jetpack_AI_Sidebar::register_provider( array() );
 
 		$this->assertCount( 1, $providers );
-		$this->assertStringContainsString( 'jetpack-ai-provider-esm.mjs', $providers[0] );
+		$this->assertStringContainsString( 'jetpack-ai-sidebar.provider.mjs', $providers[0] );
 		$this->assertTrue( wp_script_is( 'jetpack-ai-provider', 'enqueued' ) );
 		$this->assertTrue( wp_style_is( 'jetpack-ai-provider', 'enqueued' ) );
 	}
@@ -320,7 +320,7 @@ public function test_register_provider_preserves_existing_providers() {
 		$this->assertCount( 3, $providers );
 		$this->assertSame( 'https://example.com/provider-a.mjs', $providers[0] );
 		$this->assertSame( 'https://example.com/provider-b.mjs', $providers[1] );
-		$this->assertStringContainsString( 'jetpack-ai-provider-esm.mjs', $providers[2] );
+		$this->assertStringContainsString( 'jetpack-ai-sidebar.provider.mjs', $providers[2] );
 	}
 
 	// ──────────────────────────────────────────────────
@@ -386,7 +386,7 @@ public function test_full_flow_with_filter_enabled() {
 		$providers = apply_filters( 'agents_manager_agent_providers', array() );
 
 		$this->assertCount( 1, $providers );
-		$this->assertStringContainsString( 'jetpack-ai-provider-esm.mjs', $providers[0] );
+		$this->assertStringContainsString( 'jetpack-ai-sidebar.provider.mjs', $providers[0] );
 	}
 
 	/**