feat: v2.6.0 3-step AI pipeline, VPS worker, REST worker routes

- 3-step OpenRouter pipeline: Gatekeeper scoring/classification, PubMed+Google URL extraction, Markdown summary generation
- REST worker routes /wp-json/peptide-news/v1/worker/* with X-Peptide-News-Token auth
- Standalone Coolify worker (tools/vps-worker) with Dockerfile + docker-compose
- CLI commands, content extractor, pubmed extractor, google url resolver
- 89 PHPUnit tests passing

tests/unit/CliCommandsTest.php

@@ -0,0 +1,24 @@
+<?php
+/**
+ * Unit tests for Peptide_News_CLI commands.
+ *
+ * @since 2.6.0
+ */
+
+use PHPUnit\Framework\TestCase;
+
+class CliCommandsTest extends TestCase {
+
+	public function test_cli_class_exists_and_extends_command(): void {
+		$this->assertTrue( class_exists( 'Peptide_News_CLI' ) );
+		$cli = new Peptide_News_CLI();
+		$this->assertInstanceOf( 'WP_CLI_Command', $cli );
+	}
+
+	public function test_cli_methods_exist(): void {
+		$cli = new Peptide_News_CLI();
+		$this->assertTrue( method_exists( $cli, 'fetch' ) );
+		$this->assertTrue( method_exists( $cli, 'process_llm' ) );
+		$this->assertTrue( method_exists( $cli, 'backfill_sources' ) );
+	}
+}