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/810_dyn.c

@@ -1,19 +1,12 @@
 /*
- * 810_dyn — end-to-end test of w6l's dynamic linker.
+ * Covers the claims the exit status alone can't show: dyn.c reading
+ * ET_DYN and extracting exports, PLT/GOT generation with JUMP_SLOT
+ * relocations, and PT_INTERP/PT_DYNAMIC emission.
  *
- * Drives `ww build -L /usr/lib -l c` over a small ww program that
- * binds libc symbols via @symbol, then runs the produced binary and
- * checks the exit status. Verifies:
- *
- *   - the .so loader (dyn.c) reads ET_DYN and extracts exports
- *   - PLT/GOT generation and the JUMP_SLOT relocation
- *   - PT_INTERP/PT_DYNAMIC emission
- *   - symbol versioning (.gnu.version + .gnu.version_r) — clock_gettime
- *     has both GLIBC_2.2.5 (compat) and GLIBC_2.17 (default) on glibc;
- *     the loader requires the right .gnu.version_r entry to bind
- *     the default vDSO-aware impl.
- *
- * Reports the harness skip status on systems without a supported libc.so.6.
+ * Symbol versioning (.gnu.version + .gnu.version_r): clock_gettime has
+ * both GLIBC_2.2.5 (compat) and GLIBC_2.17 (default) on glibc; the
+ * loader requires the right .gnu.version_r entry to bind the default
+ * vDSO-aware impl.
  */
 #include <stdio.h>
 #include <stdlib.h>
@@ -122,7 +115,6 @@ main(void)
 		bin = absbin;
 	}
 
-	/* Probe each common libc dir to find the right -L. */
 	const char *libdir = NULL;
 	if (access("/usr/lib/libc.so.6", 0) == 0) libdir = "/usr/lib";
 	else if (access("/lib/x86_64-linux-gnu/libc.so.6", 0) == 0) libdir = "/lib/x86_64-linux-gnu";