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/object/elfobj_test.ww

@@ -147,8 +147,6 @@ fn iself64(o: str) bool = {
 		&& o[3] == 0x46u8 && o[4] == 2u8;
 };
 
-// ---- elf64header (500) -------------------------------------------------
-
 @test fn elf64header() void = {
 	let td: str = testenv.fresh();
 	let programs: []str = [
@@ -184,8 +182,6 @@ fn iself64(o: str) bool = {
 	testenv.clean(td);
 };
 
-// ---- dataw (510) -------------------------------------------------------
-
 @test fn dataw() void = {
 	let td: str = testenv.fresh();
 	let src: str = strings.concat(td, "/dataw.s");
@@ -246,8 +242,6 @@ fn iself64(o: str) bool = {
 	testenv.clean(td);
 };
 
-// ---- nodataw (510) -----------------------------------------------------
-
 @test fn nodataw() void = {
 	let td: str = testenv.fresh();
 	let src: str = strings.concat(td, "/nodataw.s");
@@ -272,8 +266,6 @@ fn iself64(o: str) bool = {
 	testenv.clean(td);
 };
 
-// ---- datar (520) -------------------------------------------------------
-
 @test fn datar() void = {
 	let td: str = testenv.fresh();
 	let src: str = strings.concat(td, "/datar.s");