Give the user menu one door into settings instead of three

Settings, Vaults and Preferences all opened the same full-window settings mode
and differed only in which of its seven pages they landed on. SettingsNav, which
lists every one of those pages including Vaults and Preferences, is on screen the
whole time you are in there — so two of the three rows were deep links into a
place the third one opens. They saved one click and cost a menu that read as
though it offered three destinations.

It was three rows for a reason that had stopped applying. Until v5c, "Settings"
and "Preferences" were two doors onto the same bare Preferences screen, and
splitting them was the fix for something real; Vaults arrived beside them when
VaultsScreen became a settings page too. Folding those two back in is not a
return to that state. They are pages now, with a rail of their own, and what a
menu at the foot of the nav rail is for is getting into settings at all.

Nothing became unreachable — both are one click deeper, from the rail that was
always going to be the way to them.

◆ WHAT STAYS, AND WHY IT IS NOT THE SAME ARGUMENT.

Logout stays and still lands on the Account page rather than on General, because
its confirmation card is drawn inline on that one page while the vault is
unlocked; arming it from anywhere else would raise a card nobody could see. The
vault switches and New vault above the divider stay too — neither is a page of
the settings mode, and the switches have no other home.

◆ THE ROWS ARE REMOVED FROM THE MARKUP, NOT UNWIRED.

NavRailTests asserts their absence rather than only asserting that Settings still
works, because the failure that guards against is silent: a row left in the
markup with its handler deleted is a menu entry that does nothing when pressed,
which reads as a broken application rather than a tidied menu. The helper it
asserts through excludes the vault switches by their data context and not by
their label — a vault is free to be called "Vaults", and a test that a menu entry
is absent must not be defeatable by what somebody named a vault.

Two facts go, one comes back plus the absence check; the layout suite is 166.

Manual check 1.8 walked a reader through all three rows in turn and now walks
them through the one, then through SettingsNav's seven — which is where the two
went. design-import-gaps.md gains a v5c-5 section rather than an edit to the v5c
table: what that table records is what shipped in that pass, and it did.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/design-import-gaps.md

@@ -741,3 +741,27 @@ to a 34-pixel rail carrying the chevron that brings it back — a rail rather th
 that vanishes without trace is one people report as lost. The choice is written through to
 `ClientSettings.SessionSidebarOpen` rather than held for the session: it is a decision about how much of the
 window a terminal gets, and one that had to be made again on every launch would not really be on offer.
+
+## v5c-5 — one door to settings, not three
+
+**The user-chip popover keeps its Settings row and has lost Vaults and Preferences.** v5c gave it three, and
+the table above records why: until that pass "Settings" and "Preferences" had been two doors onto the same
+bare screen, so splitting them was a real fix, and Vaults arrived beside them when `VaultsScreen` became a
+settings page too.
+
+Living with it made the shape of the mistake clear. All three opened the same full-window mode and differed
+only in which of its seven pages they landed on — and `SettingsNav`, which lists every one of those pages
+including Vaults and Preferences, is on screen the entire time you are in there. So two of the three rows
+were deep links into a place the third one opens, saving one click and costing a menu that read as though it
+offered three destinations. A menu at the foot of the rail is for getting into settings at all; which page
+you want is a question that has a rail of its own once you are there.
+
+Nothing became unreachable: both pages are one click deeper, from the rail that was always going to be the
+way to them. `NavRailTests` asserts the rows are gone from the markup rather than merely unwired, because a
+row left behind with no handler is a menu entry that does nothing when pressed — which reads as a broken
+application rather than a tidied menu.
+
+Logout stays, and still lands on a page rather than on General: its confirmation card is drawn inline on the
+Account page and nowhere else, so arming it from anywhere else would be a card raised where nobody could see
+it. The vault switches and **New vault** above the divider stay too — they are what the popover is for
+besides settings, and neither is a page of the settings mode.