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

Every // ---- section banner dies (132 -> 0): names carry the WHAT.
Narration deleted (filename restatements, run-with lines, what-the-
next-line-does); every ref/hare cite, task cite, divergence, ABI/
layout contract, and ownership qualifier kept (borrowed-view lines
restored where the sweep over-cut). Comment-only proven: all 442
walk-workdir .s and 32 import-probe .s byte-identical before/after;
libbyteid 56-roster all-ID.

lib/hash/crc32/crc32.ww

@@ -1,5 +1,3 @@
-// hash/crc32 — CRC-32 checksum. Pure ww.
-//
 // Same shape as lib/hash/crc16: per-byte inline polynomial shift,
 // no precomputed table. Slower than Hare's table-driven path by ~8x
 // per byte but produces identical answers.
@@ -10,9 +8,7 @@ def IEEE: u32       = 0xEDB88320u32;	// gzip, PNG, zip, Ethernet
 def CASTAGNOLI: u32 = 0x82F63B78u32;	// iSCSI, SCTP, SSE4.2
 def KOOPMAN: u32    = 0xEB31D82Eu32;	// small datasets
 
-// sum32 — fold `buf` under `poly` (reversed form). Initial cval is
-// ~0u32; per byte we mix in the low byte via 8 polynomial shifts and
-// XOR with the high three bytes shifted down.
+// sum32 — fold `buf` under `poly` (reversed form). Initial cval is ~0u32.
 export fn sum32(buf: []u8, poly: u32) u32 = {
 	let c: u32 = 0xFFFFFFFFu32;
 	let i: i32 = 0;