test: banner purge + WHY-only comment sweep (rule 8)

Every section banner dies (103 -> 0) across test/lang, the observer
suites, the C carriers, and the five comment-heavy corpus fixtures;
banner provenance (#N cites, carrier numbers, repair-cluster labels)
folded into headers or adjacent WHY comments. Narration deleted; row
provenance, ref cites, divergence pins, and layout contracts kept
(fwd-ref decl-order guards and bootstrap-gate corpus rationale
restored where the sweep over-cut). Comment-only proven: all 3742
wwbuild workdir .s byte-identical before/after; test-commit and
test-byteid (161 lang + 1399 data, 0 pinned-divergent) green.

test/wcc/996_dyn_ww.c

@@ -1,11 +1,8 @@
 /*
- * 996_dyn_ww — phase-8 marker for ET_DYN linking on the ww side.
- *
- * Drives w6l_ww with -L/-l flags over examples/mandelbrot/mandelbrot.o and diffs
- * the result against the C-built w6l on the same inputs. A green run
- * means the ww-side linker emits PT_INTERP/PT_DYNAMIC binaries byte-
- * for-byte identical to the C linker — i.e. the dynamic linking story
- * is fully ported.
+ * Phase-8 marker for ET_DYN linking on the ww side: a green run means
+ * the ww-side linker emits PT_INTERP/PT_DYNAMIC binaries byte-for-byte
+ * identical to the C linker on the same inputs — i.e. the dynamic
+ * linking story is fully ported.
  */
 #include <stdio.h>
 #include <stdlib.h>
@@ -85,7 +82,6 @@ main(void)
 		goto cleanup;
 	}
 
-	/* C-side w6l with the dynamic flags. */
 	snprintf(cmd, sizeof cmd,
 	    "%s/w6l -o %s %s -L /usr/lib "
 	    "-l c %s/out/lib/libwwrt.a 2>/dev/null",
@@ -96,7 +92,6 @@ main(void)
 		goto cleanup;
 	}
 
-	/* ww-side w6l with the same flags. */
 	snprintf(cmd, sizeof cmd,
 	    "%s/w6l_ww -o %s %s -L /usr/lib "
 	    "-l c %s/out/lib/libwwrt.a 2>/dev/null",