Wire Psalm into CI, fix a real bug it found in user-migration import

RepositoryImportSource::copyToFolder() called putContent() on the generic
return type of Node::get(), which doesn't declare that method -- only
File does. Existing-file overwrite during a per-user restore would have
fatally errored at runtime; added an instanceof check and a resource leak
fix (finally-close) while there. Also guarded getFileAsStream() against
fopen() returning false.

Everything else Psalm (strict level) currently flags is mechanical
(missing `final` on leaf classes -- applied everywhere safe) or pre-existing
array-shape/type gaps, captured in psalm-baseline.xml so CI fails only on
new issues from here on, not the whole backlog at once.

lib/Db/AppConfigCatalogAnchor.php

@@ -12,7 +12,7 @@ use OCA\NgBackup\Repository\ICatalogAnchor;
 use OCP\IAppConfig;
 
 /** Keeps the newest catalog generation seen per repository in the app config (outside the location). */
-class AppConfigCatalogAnchor implements ICatalogAnchor {
+final class AppConfigCatalogAnchor implements ICatalogAnchor {
 	public function __construct(
 		private IAppConfig $appConfig,
 	) {

lib/Db/DbIndexCache.php

@@ -11,7 +11,7 @@ use OCA\NgBackup\Repository\IIndexCache;
 use OCP\DB\Exception;
 use OCP\IDBConnection;
 
-class DbIndexCache implements IIndexCache {
+final class DbIndexCache implements IIndexCache {
 	public function __construct(
 		private IDBConnection $db,
 	) {

lib/Db/Run.php

@@ -33,7 +33,7 @@ use OCP\AppFramework\Db\Entity;
  * @method int|null getFinishedAt()
  * @method void setFinishedAt(?int $v)
  */
-class Run extends Entity {
+final class Run extends Entity {
 	public const RUNNING = 'running';
 	public const DONE = 'done';
 	public const FAILED = 'failed';

lib/Db/RunMapper.php

@@ -12,7 +12,7 @@ use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 
 /** @template-extends QBMapper<Run> */
-class RunMapper extends QBMapper {
+final class RunMapper extends QBMapper {
 	public function __construct(IDBConnection $db) {
 		parent::__construct($db, 'ngb_runs', Run::class);
 	}

lib/Db/Snapshot.php

@@ -25,7 +25,7 @@ use OCP\AppFramework\Db\Entity;
  * @method int|null getBytes()
  * @method void setBytes(?int $v)
  */
-class Snapshot extends Entity {
+final class Snapshot extends Entity {
 	protected int $targetId = 0;
 	protected string $snapshotId = '';
 	protected string $kind = '';

lib/Db/SnapshotMapper.php

@@ -12,7 +12,7 @@ use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 
 /** @template-extends QBMapper<Snapshot> */
-class SnapshotMapper extends QBMapper {
+final class SnapshotMapper extends QBMapper {
 	public function __construct(IDBConnection $db) {
 		parent::__construct($db, 'ngb_snapshots', Snapshot::class);
 	}

lib/Db/Target.php

@@ -29,7 +29,7 @@ use OCP\AppFramework\Db\Entity;
  * @method int getCreatedAt()
  * @method void setCreatedAt(int $v)
  */
-class Target extends Entity {
+final class Target extends Entity {
 	protected string $name = '';
 	protected string $backend = '';
 	protected string $auth = '';

lib/Db/TargetMapper.php

@@ -11,7 +11,7 @@ use OCP\AppFramework\Db\QBMapper;
 use OCP\IDBConnection;
 
 /** @template-extends QBMapper<Target> */
-class TargetMapper extends QBMapper {
+final class TargetMapper extends QBMapper {
 	public function __construct(IDBConnection $db) {
 		parent::__construct($db, 'ngb_targets', Target::class);
 	}