docs(rust): plan fixes — D169-D172, the org lead's answers

D169 every fix and redesign lands before Module-Rust's cutover. D170 an
expired zone is marked expired on the site (F14 moves from "by design"
to a fix, amending D96). D171 Steam sign-in moves to the website's own
plan as part of the base website. D172 chat titles use all twenty-three
listed conditions under new names: §4.6 is now a table of condition,
title and the hook that feeds it, plus what the detailed plan must
settle (best-value columns, weapon classes, vehicle-kill credit, heals
of others, quests). PLAN.md §35 and the rust README follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

modules/rust/README.md

@@ -24,7 +24,7 @@ differ.
 for actually building `module-rust`. Everything else in this directory is copied from uMod; those two
 are written by this project and are where the phases, the settled decisions and the local test rig are
 recorded. [`PLAN_FIXES.md`](PLAN_FIXES.md) is its companion: the first player walk's fixes and decisions
-D159–D168, planned to land before the Module-Rust cutover.
+D159–D172, all to land before the Module-Rust cutover.
 
 > **This is a mirror, not a specification we own.** uMod is upstream and wins any disagreement; the
 > point of copying it is availability and grep-ability, not authority. Nothing here may be cited as a