v0.19.2 - Phase 2 admin M2: Article Dossier + class-prautoblogger split (#158)

Article dossier (Proposal C): per-stage input/output sections w/ raw-trace
toggle, metadata sidebar + per-stage cost receipt, run_decisions rationale,
image section, metabox dossier link, board deep-links. DB-migration methods
extracted to class-db-migrations.php (byte-parity verified by QA).

QA: APPROVE-W-P2 qa-reviews/prautoblogger/2026-06-12-579c66e.md
P2s carried to M3: populate request_json (input trace), sidebar pv
consolidation, image stages in run_stages. Thread: pipeline-v2-phase2-admin seq 16-20

Agent-Session: cto-phase2-admin-m2-merge-20260612

templates/admin/metabox-dossier-link.php

@@ -0,0 +1,41 @@
+<?php
+/**
+ * Post metabox template (slimmed, M2): "View generation dossier" link.
+ *
+ * The full generation record is available on the Article Dossier page.
+ * This metabox replaces the previous inline metadata display to avoid
+ * duplicating data that lives in the dossier.
+ *
+ * @see admin/class-post-metabox.php          -- Renders this template.
+ * @see admin/class-dossier-page.php           -- Dossier target page.
+ *
+ * @var WP_Post $post The current post.
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+$run_id = (string) get_post_meta( $post->ID, '_prautoblogger_run_id', true );
+$url    = PRAutoBlogger_Dossier_Page::url_for_post( $post->ID );
+?>
+<div class="prab-metabox-dossier">
+	<?php if ( '' !== $run_id ) : ?>
+		<p>
+			<a href="<?php echo esc_url( $url ); ?>" class="button button-secondary">
+				<?php esc_html_e( 'View generation dossier', 'prautoblogger' ); ?> &rarr;
+			</a>
+		</p>
+		<p class="description prab-run-id-label">
+			<?php
+			printf(
+				/* translators: %s: run UUID */
+				esc_html__( 'Run: %s', 'prautoblogger' ),
+				esc_html( $run_id )
+			);
+			?>
+		</p>
+	<?php else : ?>
+		<p class="description"><?php esc_html_e( 'No generation record — article was not created by PRAutoBlogger.', 'prautoblogger' ); ?></p>
+	<?php endif; ?>
+</div>