A message beside its open editor stands in the browser too (improvise-1x9h)

The toast hid every status after six seconds, so a refusal the user was
still fixing vanished with its prompt open: su4u's bug on a timer. The
browser now asks the TUI's question. EditorSession moves into
improvise-protocol, ClientState records which editor a status was
written in, and RenderModel::status_stands tells the toast to hold it
until that editor closes.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

web/shell.js

@@ -16,7 +16,10 @@ export const TOAST_MS = 6000;
 
 /** `ViewState::status_msg` is STATE, not an event: a repaint re-offers the
  *  string that is already on screen, so dismissal keys off message IDENTITY
- *  and never off a timer alone. What that costs: context/code/clients.md. */
+ *  and never off a timer alone. What that costs: context/code/clients.md.
+ *
+ *  `stands` is Rust's answer (`RenderModel::status_stands`): while it holds the
+ *  message is on no timer, and when it stops the message goes (improvise-1x9h). */
 export function createToasts({
   onShow,
   onHide,
@@ -28,12 +31,21 @@ export function createToasts({
   // mechanism: a repaint offering it again is recognised and dropped.
   let offered = "";
   let timer = null;
+  let standing = false;
 
   return {
-    offer(text) {
+    offer(text, stands = false) {
       const next = text ?? "";
-      if (next === offered) return;
+      if (next === offered) {
+        // Standing ends once: the editor it belonged to has closed.
+        if (standing && !stands) {
+          standing = false;
+          onHide();
+        }
+        return;
+      }
       offered = next;
+      standing = next !== "" && stands;
       clearTimer(timer);
       timer = null;
       if (next === "") {
@@ -41,6 +53,7 @@ export function createToasts({
         return;
       }
       onShow(next);
+      if (standing) return;
       timer = setTimer(() => {
         timer = null;
         onHide();
@@ -349,8 +362,8 @@ export function createShell({
     setShell(text) {
       onShell(text);
     },
-    setModel(text) {
-      onModel(text);
+    setModel(text, stands = false) {
+      onModel(text, stands);
     },
     /** A peer that never answers the handshake. Deliberately about the *first
      *  frame*, not either peer's own failure modes — clients.md. */