feat(phase2b): P2b.1 — Research_Fanout + Research_Judge (curate stage) (#178, v0.28.0)

Additive: parallel research fan-out (curl_multi, quorum, cost-reserve-before-dispatch) + curate judge (dedup/score/run_sources). Live Economy path untouched; Authority activates at P2b.4. QA APPROVE-WITH-P2 685c40b; CI green (PHPUnit verified on VPS runner).

Agent-Session: prab-phase2b-1-merge

includes/providers/interface-research-judge.php

@@ -0,0 +1,26 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * Contract for the research judge that curates fan-out results.
+ *
+ * @see core/class-research-judge.php — Primary implementation.
+ * @see ARCHITECTURE.md               — Phase 2b curate stage.
+ */
+interface PRAutoBlogger_Research_Judge_Interface {
+
+	/**
+	 * Deduplicate and score the fan-out results; write keep/discard decisions
+	 * to run_sources; return kept sources for the draft stage.
+	 *
+	 * @param string $run_id   Run UUID.
+	 * @param string $item_key Article-scoped item key.
+	 * @param array<int, array{sources: array<int, array{url: string, title: string, excerpt: string, relevance: float}>, agent_role: string}> $fanout_results Agent results from Research_Fanout::dispatch().
+	 * @return array<int, array{url: string, title: string, excerpt: string, relevance: float, quality_score: float}> Kept, deduplicated, scored sources.
+	 */
+	public function curate(
+		string $run_id,
+		string $item_key,
+		array $fanout_results
+	): array;
+}