chore: comments say what the code does, not which task produced it

A comment that reads "MUST stay in lockstep with TryGetActiveCrossfade (K8)"
helps nobody outside the plan that used to have a K8 in it, and the plans are
not in this repo. Same for "Spec FR-4", "plan §B.2", "Sub-Task 4.4" and the
F/R/M/A/S round codes scattered through the style engine and the self-tests.

Personal names go too. "tester feedback from Jin (v1.4.7)" and "Flo decision
2026-06-15" carry the reason fine without naming anyone -- the version and the
reason are the parts a reader can act on, and a public repo should not need a
cast list to be read.

The rule applied throughout: keep the why, drop the reference. Version numbers
stay, since those resolve through the changelog. 77 files.

ChunkUtil also carried 281 lines of commented-out code -- an older ToChunks
variant and two helpers with no callers, inherited and never removed. Deleted;
git remembers them.

HellionChat/SelfTests/CurrentTabGuidedStep.cs

@@ -5,12 +5,12 @@ using HellionChat.GameFunctions.Types;
 
 namespace HellionChat.SelfTests;
 
-// F2 (guided): interactive, fires NO synthetic probes. Shows the full measured
+// Guided: interactive, fires NO synthetic probes. Shows the full measured
 // state every frame so a result is observable, not a guess, and walks the user
 // through the real switch-away-and-back flow. It verifies the PRIVACY-relevant
 // effect, keyed on the tab type:
 //   - a NORMAL tab carrying a game-side tell must lose its RUNTIME target
-//     (CurrentChannel.TellTarget) on switch-away-and-back (the F1 strip), so a
+//     (CurrentChannel.TellTarget) on switch-away-and-back, so a
 //     typed line can't /tell the old partner;
 //   - a BOUND auto-tell tab keeps its partner by design (leg1) — its binding is
 //     Tab.TellTarget and is deliberately untouched by the strip.