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

selfhost/, cmd/, internal/ join the tree-wide sweep: every section
banner dies (91 selfhost + the cmd C-style dividers -> 0); narration
and stale contracts deleted (pre-#22 bundler notes, retired
single-PT_LOAD and no-archive claims, superseded ABI tables); every
ref/harec/qbe cite, task cite, encoding/ELF contract, and rule-10
twin pointer kept; lost lifetime/rationale lines restored where the
sweep over-cut (elf_globals ownership, kwtab linear-scan). Comment-
only proven: all five wwstage tool binaries byte-identical across
the sweep; test-commit, test-byteid (161+1399, 0 pinned-divergent),
and test-bootstrap (fixed point + 991-995 byte-id) all exit 0.
The read-through banked 66 latent-bug leads (checkpoint).

cmd/w6l/out.c

@@ -1,6 +1,4 @@
 /*
- * out.c — emit a static ELF64 executable.
- *
  * Layout (file order) without .data:
  *   [0..64)       ELF header
  *   [64..120)     one program header (PT_LOAD R+X)
@@ -13,9 +11,6 @@
  *   [176..0x1000)  zero pad
  *   [0x1000..)     .text bytes
  *   [data_off..)   .data bytes (file offset and vaddr page-aligned)
- *
- * No interpreter, no dynamic, no .bss yet. Entry point is the address
- * of the symbol named "_start" (or whatever main supplies via -e).
  */
 #include "l.h"
 #include <stdio.h>
@@ -102,9 +97,6 @@ l_emit_elf(Lnk *l, FILE *f, u64 base, u64 entry)
 	eh.e_phentsize = sizeof(Phdr);
 	eh.e_phnum = has_data ? 2 : 1;
 
-	/* R+X load covering [0, rx_end). When .data is present we still
-	 * round up to a page in memsz so the loader doesn't try to give
-	 * the same page both R+X and R+W permissions. */
 	Phdr phx = {0};
 	phx.p_type = PT_LOAD;
 	phx.p_flags = PF_R | PF_X;
@@ -131,14 +123,12 @@ l_emit_elf(Lnk *l, FILE *f, u64 base, u64 entry)
 	fwrite(&phx, 1, sizeof phx, f);
 	if (has_data) fwrite(&phw, 1, sizeof phw, f);
 
-	/* pad to text_off */
 	long here = ftell(f);
 	for (long i = here; i < (long)text_off; i++) fputc(0, f);
 
 	if (l->textlen) fwrite(l->text, 1, l->textlen, f);
 
 	if (has_data && data_file_len > 0) {
-		/* pad to data_off */
 		here = ftell(f);
 		for (long i = here; i < (long)data_off; i++) fputc(0, f);
 		fwrite(l->data, 1, data_file_len, f);