Bump version to 1.17.8

- Feat: Verbrauchsauswertung – Ablesung korrigieren (Datum, Zählerstand,
  Korrekturnotiz) und löschen direkt aus der Tabelle (manage_kleingarten)
- Feat: Inventarverwaltung – Gegenstände erfassen, bearbeiten, löschen;
  Ausleihe und Rückgabe je Mitglied mit Notiz und Fälligkeitsdatum tracken;
  Export/Import integriert (InventoryRepository, Schema, Validator, DataTransfer)
- Feat: Jahresabrechnung Sperrstatus – Festschreiben/Freigeben mit
  serverseitiger Prüfung aller Schreibzugriffe auf Kosten und Preise

includes/Repositories/CostRepository.php

@@ -222,6 +222,75 @@ class CostRepository extends AbstractRepository {
 		return $this->wpdb->get_row( $this->wpdb->prepare( "SELECT * FROM {$year_table} WHERE entry_year = %d", $year ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
 	}
 
+	/**
+	 * Get lock state for one statement year.
+	 *
+	 * @param int $year Selected year.
+	 * @return array
+	 */
+	public function get_statement_lock_state( $year ) {
+		$details = $this->get_year_details( $year );
+
+		if ( ! $details ) {
+			return array(
+				'is_locked' => false,
+				'locked_at' => null,
+				'locked_by' => 0,
+			);
+		}
+
+		return array(
+			'is_locked' => ! empty( $details->statement_is_locked ) && 1 === (int) $details->statement_is_locked,
+			'locked_at' => isset( $details->statement_locked_at ) ? $details->statement_locked_at : null,
+			'locked_by' => isset( $details->statement_locked_by ) ? (int) $details->statement_locked_by : 0,
+		);
+	}
+
+	/**
+	 * Check whether statement data for one year is locked.
+	 *
+	 * @param int $year Selected year.
+	 * @return bool
+	 */
+	public function is_statement_locked( $year ) {
+		$state = $this->get_statement_lock_state( $year );
+
+		return ! empty( $state['is_locked'] );
+	}
+
+	/**
+	 * Lock or unlock a statement year.
+	 *
+	 * @param int  $year       Selected year.
+	 * @param bool $is_locked  Target lock state.
+	 * @param int  $locked_by  User ID that changes the state.
+	 * @return bool
+	 */
+	public function set_statement_lock( $year, $is_locked, $locked_by = 0 ) {
+		$year = absint( $year );
+
+		if ( $year < 1 || ! $this->ensure_year( $year ) ) {
+			return false;
+		}
+
+		$payload = array(
+			'statement_is_locked' => $is_locked ? 1 : 0,
+			'statement_locked_at' => $is_locked ? $this->now() : null,
+			'statement_locked_by' => $is_locked ? absint( $locked_by ) : 0,
+			'updated_at'          => $this->now(),
+		);
+
+		$result = $this->wpdb->update(
+			$this->year_table(),
+			$payload,
+			array( 'entry_year' => $year ),
+			array( '%d', '%s', '%d', '%s' ),
+			array( '%d' )
+		);
+
+		return false !== $result;
+	}
+
 	/**
 	 * Save section-specific yearly prices.
 	 *