feat: add @Tag reporting and CSV/plain output

- Default CSV output with header; -plain enables labeled text format
- Extract repeated @Tag and @Tags container values
- Configure JavaParser language level for modern syntax (records)
- Add fixture-based JUnit tests and README usage/examples

.gitattributes

@@ -0,0 +1,12 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+
+# Binary files should be left untouched
+*.jar           binary
+