style(layout): borderless WorkspaceSwitcher with hover/open background; fix avatar jump

Matches the crewli-starter SoT and fixes the recurring collapse jump at
its root cause. The prior structures left a residual avatar shift:
- the original split put the avatar at 24px expanded (wrapper px-4 +
  card p-2) vs 16px collapsed (bare square) — an 8px horizontal jump;
- the interim single-trigger variant used wrapper p-[10px] + trigger
  px-[10px] expanded (~20px) vs justify-center collapsed (16px) — a
  ~4px residual horizontal shift.

Unified both states to a single symmetric structure:

    avatar offset = wrapper px-2 (8px) + trigger p-2 (8px) = 16px

16px from the rail's left edge in BOTH states — identical to the
SidebarHeader brand logo. Because the padding is symmetric (8 + 8 each
side) and the collapsed rail is 64px = 16 + 32 + 16, the left-aligned
avatar is also visually centred when collapsed — no justify-center,
no px swap, no horizontal shift; constant vertical padding, no vertical
shift. The jump is gone at the root.

Borderless: the trigger has NO border in any state (the prior is-open
border is dropped per the starter screenshots). The only divider is the
wrapper's border-t between the switcher and the nav. The grey
background is the sole fill — transparent at rest, grey on hover, and
grey while the popover is open (isOpen wired to Popover @show/@hide).
The trigger's p-2 gives the grey background generous padding around the
avatar+text, matching the starter's hover treatment, and since it is
the button's own background it never moves the content.

Specs reworked: trigger p-2 identical across states (no px swap / no
justify-center — the no-jump lock), wrapper carries p-2, trigger is
borderless at rest AND while open, open-state grey background applies
on @show and clears on @hide. Single-.trigger / rounded-lg / collapsed-
hides-meta+chev / sub-line specs retained.

Suite delta: 571 → 571 (specs reworked, count unchanged). vue-tsc
clean. Scoped ESLint clean (0 errors). Desktop only.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/app/src/components-v2/layout/WorkspaceSwitcher.vue

@@ -161,43 +161,41 @@ function inviteUser(): void {
 
 <template>
   <!--
-    Crewli-starter-faithful structure (P6-styling-switcher-sub follow-up).
-    ONE `.trigger` button renders in BOTH states — collapsing only hides
-    `.meta` + `.chev` (v-if) and recentres the lone avatar. This is the
-    key fix for the vertical "avatar jump": the prior version swapped
-    between two separate <button> elements (a bare collapsed button vs a
-    padded expanded trigger) with different box models, so the avatar's
-    distance from the rail bottom differed by ~6px and visibly jumped on
-    collapse. With a single trigger and constant vertical padding
-    (`py-2` always), the avatar stays put.
+    Unified borderless structure (P6-styling-switcher-hover, crewli-starter
+    SoT). ONE `.trigger` button renders in BOTH states; collapsing only
+    hides `.meta` + `.chev` (v-if). The button keeps the SAME padding in
+    both states — this is what kills the avatar jump:
 
-    Wrapper: `border-t` separator + `p-[10px]` ALWAYS (constant vertical
-    padding → no jump; matches crewli-starter `.ws-switcher { padding:
-    10px }`). No border around the wrapper itself.
+    avatar offset = wrapper px-2 (8px) + trigger p-2 (8px) = 16px
 
-    Centring equation (collapsed): wrapper p-[10px] gives the trigger a
-    44px content width inside the 64px rail; the trigger's `justify-center
-    px-0` centres the 32px avatar → 16px from the rail's left edge,
-    aligned with the SidebarHeader brand logo above (also 16px).
+    16px from the rail's left edge in BOTH collapsed and expanded —
+    identical to the SidebarHeader brand logo (px-4). Because the
+    horizontal padding is symmetric (8 + 8 each side) and the rail
+    collapses to 64px = 16 + 32 (avatar) + 16, the left-aligned avatar
+    is ALSO visually centred when collapsed — no justify-center swap, no
+    horizontal shift. Vertical padding is likewise constant, so no
+    vertical shift either. The earlier 24px-expanded / 16px-collapsed
+    split (and the later px-[10px]/justify-center variant) both left a
+    residual shift; this symmetric structure removes it entirely.
+
+    Borderless: the trigger has NO border in any state (the prior
+    is-open border is dropped per the starter screenshots). The only
+    divider is the wrapper's `border-t` separating the switcher from the
+    nav above. The grey background is the sole fill, on hover OR while
+    the popover is open.
   -->
-  <div class="ws-switcher relative flex-shrink-0 border-t border-[var(--p-content-border-color)] p-[10px]">
+  <div class="ws-switcher relative flex-shrink-0 border-t border-[var(--p-content-border-color)] p-2">
     <!--
-      Trigger — single button for both states (crewli-starter `.trigger`).
-      Resting: transparent border + transparent bg. Hover: grey bg, no
-      border. Open (is-open): grey bg KEPT + visible border, persisting
-      until the popover closes — crewli-starter
-      `.ws-switcher.is-open .trigger { background; border-color }`.
-      `py-2` is constant; only horizontal padding / justify changes on
-      collapse, so the avatar never shifts vertically.
+      Trigger — single button for both states. Transparent at rest; grey
+      on hover; grey KEPT while the popover is open (isOpen, wired to the
+      Popover @show/@hide). The `p-2` gives the grey background generous
+      padding around the avatar+text (crewli-starter hover treatment),
+      and because the background is the button's own bg (not a separate
+      shifting layer) it never moves the avatar.
     -->
     <button
-      class="trigger flex w-full items-center gap-[10px] rounded-lg border bg-transparent py-2 text-[var(--p-text-color)] transition-[background,border-color] duration-150 focus-visible:outline focus-visible:outline-2 focus-visible:outline-[var(--p-primary-color)] focus-visible:outline-offset-2"
-      :class="[
-        collapsed ? 'justify-center px-0' : 'px-[10px]',
-        isOpen
-          ? 'is-open border-[var(--p-content-border-color)] bg-[var(--p-content-hover-background)]'
-          : 'border-transparent hover:bg-[var(--p-content-hover-background)]',
-      ]"
+      class="trigger flex w-full items-center gap-[10px] rounded-lg bg-transparent p-2 text-[var(--p-text-color)] transition-colors duration-150 hover:bg-surface-100 dark:hover:bg-surface-800 focus-visible:outline focus-visible:outline-2 focus-visible:outline-[var(--p-primary-color)] focus-visible:outline-offset-2"
+      :class="{ 'bg-surface-100 dark:bg-surface-800': isOpen }"
       aria-haspopup="true"
       :aria-expanded="isOpen"
       :aria-label="collapsed && current ? `Workspace: ${current.name}` : undefined"