v0.3.0 — cost accountability + LLM call audit trail (#7)

Per-call recording of cost and I/O for every LLM probe. New tables prv_call_meta (schema v3) and prv_call_io. New admin pages: Costs (spend drill-down vs $5 cap) and Call Log (paginated + detail drawer). 90-day I/O retention prune via prv_daily_prune cron. P0 security: key never stored; gateway client exposes HTTP status only.

QA APPROVED 2026-06-15 SHA 09dc6db9ce

includes/core/class-prv-prune-cron.php

@@ -0,0 +1,118 @@
+<?php
+/**
+ * Daily prune cron: delete aged prv_call_io rows (v0.3.0).
+ *
+ * @package PrVision
+ */
+
+declare(strict_types=1);
+
+/**
+ * Manages the daily prune cron that deletes aged prv_call_io rows.
+ *
+ * Retention window is set in Settings (default 90 days). Only prv_call_io
+ * rows are deleted — prv_call_meta (cost/metadata) is kept indefinitely.
+ * The cron is idempotent: calling schedule() when already scheduled is safe.
+ *
+ * Cleared in the deactivator AND uninstall so no orphan cron events remain.
+ *
+ * Who triggers: PRV_Activator (schedule), PRV_Deactivator (clear),
+ *               uninstall.php (clear), self::handle_prune_tick() (prune).
+ * Dependencies: $wpdb, PRV_Call_Io_Table, PRV_Config.
+ *
+ * @see class-prv-call-io-table.php — Table from which aged rows are deleted.
+ * @see class-prv-config.php        — get_io_retention_days() for the window.
+ * @see class-prv-activator.php     — Calls schedule() on activation.
+ * @see class-prv-deactivator.php   — Calls clear_schedule() on deactivation.
+ * @see uninstall.php               — Calls clear_schedule() on uninstall.
+ * @package PrVision
+ */
+class PRV_Prune_Cron {
+
+	/**
+	 * WP-Cron hook name for the daily prune event.
+	 */
+	const PRUNE_HOOK = 'prv_daily_prune';
+
+	/**
+	 * Register the cron action hook.
+	 *
+	 * Side effects: Adds action for PRV_PRUNE_HOOK.
+	 *
+	 * @return void
+	 */
+	public function register_hooks(): void {
+		add_action( self::PRUNE_HOOK, array( $this, 'handle_prune_tick' ) );
+	}
+
+	/**
+	 * Callback fired by WP-Cron daily.
+	 *
+	 * Deletes prv_call_io rows older than the configured retention window.
+	 * Safe to re-run — idempotent on already-pruned data.
+	 *
+	 * Side effects: Database delete on prv_call_io.
+	 *
+	 * @return int Number of rows deleted.
+	 */
+	public function handle_prune_tick(): int {
+		return self::prune_now();
+	}
+
+	/**
+	 * Perform the prune immediately (used by handle_prune_tick + tests).
+	 *
+	 * Deletes only prv_call_io rows; prv_call_meta is never touched.
+	 *
+	 * Side effects: Database delete on prv_call_io.
+	 *
+	 * @return int Number of rows deleted (0 when nothing to prune).
+	 */
+	public static function prune_now(): int {
+		global $wpdb;
+
+		$days  = PRV_Config::get_io_retention_days();
+		$table = PRV_Call_Io_Table::get_table_name();
+
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
+		$deleted = $wpdb->query(
+			$wpdb->prepare(
+				// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+				"DELETE FROM {$table} WHERE captured_at < DATE_SUB(UTC_TIMESTAMP(), INTERVAL %d DAY)",
+				$days
+			)
+		);
+
+		return (int) $deleted;
+	}
+
+	/**
+	 * Schedule the daily prune event.
+	 *
+	 * Safe to call on re-activation — no-op when already scheduled.
+	 * Side effects: Adds a WP-Cron daily event.
+	 *
+	 * @return void
+	 */
+	public static function schedule(): void {
+		if ( ! wp_next_scheduled( self::PRUNE_HOOK ) ) {
+			wp_schedule_event( time(), 'daily', self::PRUNE_HOOK );
+		}
+	}
+
+	/**
+	 * Remove the prune cron schedule.
+	 *
+	 * Called on deactivation and uninstall.
+	 * Side effects: Removes the WP-Cron event.
+	 *
+	 * @return void
+	 */
+	public static function clear_schedule(): void {
+		$timestamp = wp_next_scheduled( self::PRUNE_HOOK );
+		if ( false !== $timestamp ) {
+			wp_unschedule_event( $timestamp, self::PRUNE_HOOK );
+		}
+		wp_clear_scheduled_hook( self::PRUNE_HOOK );
+	}
+}