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/math/random/random.ww

@@ -9,11 +9,9 @@ package random;
 
 export type random = u64;
 
-// init — initialize a generator with `seed`. Same seed reproduces the
-// same sequence on every run. Mirrors Hare's random::init.
+// Mirrors Hare's random::init.
 export fn init(seed: u64) random = { return seed: random; };
 
-// next — return a pseudo-random 64-bit value and advance the state.
 // SplitMix64, per Hare's random::next.
 export fn next(r: *random) u64 = {
 	let s: u64 = (*r): u64 + 0x9E3779B97F4A7C15u64;