style: fix include order in all source files

Move C stdlib headers before local/project headers with a
blank line separator, matching the AGENTS.md include order rule.

Replace em dash with colon in main.c comment.

tests/test_logger.c

@@ -1,4 +1,5 @@
 #include "unity.h"
+
 #include "ctdd/logger.h"
 #include "Mocklog_write.h"
 

tests/test_report.c

@@ -1,4 +1,5 @@
 #include "unity.h"
+
 #include "ctdd/report.h"
 #include "Mocklogger.h"
 

tests/test_str.c

@@ -1,4 +1,5 @@
 #include "unity.h"
+
 #include "ctdd/str.h"
 
 void setUp(void) {}