fix: move file docblocks to immediately after <?php (before declare)

PHPCS Squiz.Commenting.FileComment requires the file docblock to be the
FIRST token after the opening <?php tag. Having declare(strict_types=1)
before the docblock means PHPCS sees no file docblock at all.

Fix: in every includes/*.php file, insert a minimal /** @package ... */
docblock immediately after <?php (no blank line = satisfies SpacingAfterOpen)
with a blank line after it (satisfies SpacingAfterComment), then declare()
then the class docblock.

Also fixes peptide-repo-core.php SpacingAfterOpen/SpacingAfterComment
by removing the blank line between <?php and the existing file docblock
and ensuring one blank line after it.

Agent-Session: claude-adopt-ci-20260616

includes/admin/class-pr-core-settings-renderer.php

@@ -1,4 +1,8 @@
 <?php
+/**
+ * @package Peptide_Repo_Core
+ */
+
 declare(strict_types=1);
 
 /**