fix(tabs): grouped rail interaction fixes for inline rename

Two problems with renaming a tab in the vertical rail, both easier to hit now
that the grouped rail has its own inline editor beside the session one.

Writes. A committed rename PUT its name and only applied the answer if the
same editor was still open when it came back. Reopening the editor before the
PUT answered (F2 or right-click again, or starting a group rename, which
cancels the session editor) threw the confirmed name away, so the tab kept
showing the old name until an SSE frame happened to repaint it. Two quick
renames also raced as two concurrent PUTs. Inline renames now go through a
per-session queue: one PUT at a time in the order they were made, the
confirmed name applied to app.sessions whatever happened to the editor, and
the "already that name" check made when the write runs rather than when Enter
is pressed, so confirming the name still on screen over a write in flight is
a real write.

Layout. The editor (a flex row) could not shrink below the input's intrinsic
width, so a long w<n>-<case> prefix pushed the label past its row: the prefix
slid out of view in the detailed rows and the input was clipped mid-word in
the compact rail. The label now has min-width 0, the prefix gives way first
(down to 2rem, with an ellipsis), the input keeps 4rem, and in the compact
rail the row's adornments step aside while the name is edited. The detailed
rows' three-line clamp also outranked the shared unclamp rule, which is what
the existing "unclamped editor" browser test caught; it is restated there.

Header strip, sidebar and flat-rail markup are unchanged.

Tests (test/inline-rename.test.ts, browser suite): the unclamp check runs for
simple and detailed rows; a write-ordering describe covers ordering, a
reopened editor cancelled over a confirmed write, a re-sent unchanged name and
a group rename taking over; a long-prefix describe drives real rows from a
live session in simple, detailed and compact rails.

src/web/public/styles.css

@@ -1848,22 +1848,52 @@ html[data-tab-orientation='vertical'] .tab-rail .session-tab .tab-name-prefix {
   -webkit-line-clamp: unset;
   line-clamp: unset;
   overflow: visible;
+  /* An input's intrinsic width counts toward the label's min-content, so with
+     the default min-width:auto a long `w<n>-<case>` prefix plus the input
+     pushed the label past its row: the prefix slid out of view and, in the
+     compact rail, the input was clipped mid-word. */
+  min-width: 0;
 }
 
+/* The prefix gives way first, down to a stub with an ellipsis. */
 :is(
   html[data-tab-orientation='vertical'] .tab-rail,
   html[data-session-list='sidebar'] .session-sidebar
 ) .tab-name-renaming .tab-rename-prefix {
-  flex: 0 0 auto;
+  flex: 0 1 auto;
+  min-width: 2rem;
+  max-width: 50%;
+  overflow: hidden;
+  text-overflow: ellipsis;
 }
 
+/* The input always keeps room to type. `!important` beats the editor's inline
+   `min-width: 0`, which the header strip's fixed-width editor relies on. */
 :is(
   html[data-tab-orientation='vertical'] .tab-rail,
   html[data-session-list='sidebar'] .session-sidebar
 ) .tab-name-renaming .tab-rename-input {
   flex: 1 1 0;
   width: auto;
-  min-width: 0;
+  min-width: 4rem !important;
+}
+
+/* A compact rail row has no room for both the editor and its adornments, so
+   they step aside while the name is being edited (the re-render that ends the
+   edit brings them back). */
+html[data-tab-orientation='vertical'].tab-rail-compact
+  .tab-rail
+  .session-tab:has(.tab-name-renaming)
+  :is(
+    .tab-mode,
+    .tab-exited-badge,
+    .tab-detached-badge,
+    .tab-badge,
+    .tab-subagent-badge,
+    .tab-ultracode-badge,
+    .tab-actions
+  ) {
+  display: none;
 }
 
 /* Tab folder path — hidden by default, shown via .tabs-show-folder on container */
@@ -18895,6 +18925,13 @@ html[data-tab-orientation='vertical'][data-tab-rail-detail='rich']:not(.tab-rail
   line-clamp: 3;
 }
 
+/* ...except while it is being edited: this rule outranks the shared renaming
+   rule's unclamp, so restate it (the editor is a flex row, never clamped). */
+html[data-tab-orientation='vertical'][data-tab-rail-detail='rich']:not(.tab-rail-compact) .tab-rail .session-tab .tab-name.tab-name-renaming {
+  -webkit-line-clamp: unset;
+  line-clamp: unset;
+}
+
 html[data-tab-orientation='vertical'][data-tab-rail-detail='rich']:not(.tab-rail-compact) .tab-rail .session-tab .tab-folder {
   font-size: 0.66rem;
   margin-top: 0.1rem;