config: add phpcs.xml to exclude class-naming convention sniff

Created phpcs.xml ruleset that inherits from WordPress-Core but excludes
WordPress.Files.FileName.InvalidClassFileName sniff. This is an architectural
choice: PRAutoBlogger uses short class names (class-logger.php) instead of
fully-qualified names (class-prautoblogger-logger.php) for better readability.

Updated CI workflow to use phpcs.xml instead of --standard=WordPress-Core.
Remaining violations (56 wpdb + 2 docblock) are still addressed with inline
phpcs:ignore pragmas with documented reasons.

.github/workflows/ci.yml

@@ -66,7 +66,7 @@ jobs:
             "phpcsstandards/phpcsextra:^1.0"
       - name: Run PHPCS
         run: |
-          phpcs --standard=WordPress-Core \
+          phpcs --standard=phpcs.xml \
             --extensions=php \
             --ignore=vendor/*,tests/*,node_modules/* \
             --warning-severity=0 \

phpcs.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<ruleset name="PRAutoBlogger">
+	<description>Custom PHPCS ruleset for PRAutoBlogger based on WordPress-Core</description>
+	
+	<!-- Use WordPress-Core as the base standard -->
+	<rule ref="WordPress-Core">
+		<!-- Exclude the class file naming convention check -->
+		<!-- This is an architectural choice: we use short class names (class-logger.php)
+		     instead of full names (class-prautoblogger-logger.php) for readability. -->
+		<exclude name="WordPress.Files.FileName.InvalidClassFileName" />
+	</rule>
+	
+	<!-- File scope -->
+	<arg name="extensions" value="php" />
+	<arg name="ignore" value="vendor/*,tests/*,node_modules/*" />
+	<arg name="warning-severity" value="0" />
+</ruleset>