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/path/path.ww

@@ -152,8 +152,6 @@ export fn set(buf: *buffer, items: str...) (str | error) = {
 	return push(buf, items...);
 };
 
-// ---- c3 buffer-ops (ref/hare/path/buffer.ha, stack.ha) ----------------
-
 // lifts Hare's fn-`static let buf` (buffer.ha:53-56): statically allocated,
 // overwritten on the next local() call. strconv *tos-buf precedent.
 let localbuf: [MAX]u8 = [0...];
@@ -225,7 +223,6 @@ export fn parent(buf: *buffer) (str | error) = {
 	return strings.frombytes(buf.buf[0:newend]);
 };
 
-// ---- POSIX jail (ref/hare/path/posix.ha) ------------------------------
 // POSIX-compliant dirname/basename. They do NOT normalize the input and
 // operate on plain str (no buffer), so they sit apart from the stack
 // paradigm above — same POSIX-complaint as posix.ha:7-11.