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/strings/trim_test.ww

@@ -26,7 +26,6 @@ import strings;
 	assert(!(!streq(strings.trimsuffix("hello", "hello"), "")));
 };
 
-// ---- ltrim / rtrim / trim ---------------------------------------------
 // ref/hare/strings/trim.ha:75-97. 0-arg rows (#9) pin the ASCII
 // whitespace set (' ', '\t', '\n', '\r' — ref/hare/strings/trim.ha:6).
 
@@ -167,4 +166,3 @@ import strings;
 		i += 1;
 	};
 };
-