docs(modules): re-install Oxide after an update is routine, not a finding

Org lead correction: every Rust host already updates the server and
re-installs Oxide together. Presenting that as something an operator
would be caught by talks down to the audience.

Keeps the one narrow consequence that is actually ours: app_update
leaves Oxide.Core.dll and the rest in place, so a phase-18 doctor check
that tests for oxide/ or for Oxide's assemblies passes on a server that
is mid-routine. Compare Assembly-CSharp.dll against the Oxide build.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016wDDVXWMDz82WqE1i969r4

modules/rust/PLAN.md

@@ -718,11 +718,12 @@ Three traps recorded here because each cost time before it was understood:
   original is kept at `start.bat.bak` and the path-only fix at `start.bat.broken-order-20260915`.
   With the ordering right, the run is a delta and takes minutes.
 
-- **`app_update` silently un-Oxides the server.** Oxide ships a *patched* `Assembly-CSharp.dll`, and
-  a Steam update restores Facepunch's. It does not remove `Oxide.Core.dll` and friends, so the
-  install still *looks* Oxided — it simply loads no plugins and raises no hook. **Re-extract
-  `Oxide.Rust.zip` over the tree after every `app_update`, and check the size**: on build 25230300
-  vanilla is 9,758,544 bytes and Oxide 2.0.7716's is 9,953,280.
+- **Re-extract Oxide after every `app_update`.** Updating the server and re-installing Oxide together
+  is the standard operator routine, not a discovery — Oxide ships a *patched* `Assembly-CSharp.dll`
+  and a Steam update restores Facepunch's. Recorded here only for the mechanical detail: the update
+  does **not** remove `Oxide.Core.dll` and friends, so a half-done install still *looks* Oxided while
+  loading no plugins and raising no hook. Check the size rather than the directory — on build
+  25230300 vanilla is 9,758,544 bytes and Oxide 2.0.7716's is 9,953,280.
 - **`C:\oxide_files` is a 2025-04-23 Oxide and must not be copied anywhere.** Oxide ships a patched
   `Assembly-CSharp.dll`; that bundle's is 6,842,880 bytes against the live 9,953,280, so copying it
   over a real install is a hard downgrade. `D:\rust` is already correct and needs nothing from it.
@@ -1202,18 +1203,19 @@ skeleton can start from it.
 > line as if it were the reply and discards the real one. It cost two wrong readings before it was
 > spotted. Collect every frame in a window; do not correlate one reply per identifier.
 
-### 12.1 The rig's own scripts were broken in a way the earlier diagnosis missed
+### 12.1 The rig's own script was broken in a way the earlier diagnosis missed
 
 Recorded in §4. In short: `start.bat` put `+force_install_dir` **after** `+login`, steamcmd discarded
 it, and every update run in the rig's history errored out without updating anything. The 2026-09-15
-"fix" changed the path and left the order, so it fixed nothing. Separately, `app_update` reverts
-Oxide's patched `Assembly-CSharp.dll` while leaving Oxide's own assemblies in place, which produces a
-server that looks Oxided and loads no plugins.
+"fix" changed the path and left the order, so it fixed nothing.
 
-Both matter beyond this workstation: **phase 18's installer will hit the second one.** An
-operator who updates their Rust server has silently uninstalled Oxide, and therefore our plugin.
-`doctor` should check the `Assembly-CSharp.dll` against the Oxide build, not merely that `oxide/`
-exists.
+The Oxide re-install in §4 is **not** a finding — pairing a server update with an Oxide re-install is
+the routine every Rust host already follows, and saying otherwise would be this plan talking down to
+its own audience. One narrow consequence is still worth carrying to **phase 18**: because
+`app_update` leaves `Oxide.Core.dll` and the rest in place, a `doctor` check that tests for `oxide/`
+or for Oxide's assemblies **passes on a server that is mid-routine**. Compare the
+`Assembly-CSharp.dll` against the Oxide build instead, so `doctor` reports the real state rather than
+a directory listing.
 
 ### 12.2 Four rules the R2 permission push must obey