fix(web): hide resource subscription UI when server lacks subscribe capability (#1479)

* fix(web): hide resource subscription UI when server lacks subscribe capability (#1478)

Thread a `subscriptionsSupported` flag derived from
`capabilities?.resources?.subscribe === true` from App through
InspectorView → ResourcesScreen to the leaf components. When false:

- ResourcePreviewPanel hides the Subscribe/Unsubscribe button (Refresh
  stays).
- ResourceControls omits the Subscriptions accordion section entirely,
  dropping it from `allSections` so the expand/collapse-all toggle and
  open-section bookkeeping stay correct even if a stale "subscriptions"
  entry persists from a prior subscription-capable session.

The flag defaults to true at the leaf components so existing callers,
tests, and stories keep rendering the subscription controls unless a
server is explicitly marked unsupported.

Adds unit tests and Storybook stories covering the hidden and shown
states across all three components.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(web): give the Servers screen scroll the same gutter/idle-hidden treatment (#1474)

The server grid's ScrollArea.Autosize used the default type="hover" with no
offsetScrollbars, so the scrollbar popped in on hover and overlaid the right
edge of the server cards (occluding their action icons / status badges) — the
same problem #1474 fixed for the History/Network/Logging list panels.

Apply the same `type="scroll"` + `offsetScrollbars` treatment, and reuse the
shared `expectScrollbarGutterIdleHidden` story assertion to regression-protect
the gutter + idle-hidden behavior.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(web): stop the InspectorView shell from scrolling as a whole

AppShell.Main carried Mantine's default `padding="md"` on top of the
fixed-header offset, but every screen already sizes itself to
`calc(100vh - header)` and supplies its own `xl` padding (with no
allowance for Main's padding). That extra inset pushed screen content
past the viewport, so the whole InspectorView gained a page-level
scrollbar instead of confining overflow to each screen's inner
ScrollArea.

Set the shell `padding` to 0 (Main now contributes only the header
offset, matching what the screens were built for) and clamp the Main
slot to `height: 100dvh` with `overflow: hidden` in the theme, so the
view can never scroll regardless of content — only the inner ScrollArea
regions do.

Adds an InspectorView story play assertion guarding the invariant
(Main clips + is viewport-clamped) and a ManyServers fixture that
confirms it holds under enough content to overflow, with the inner
server-grid ScrollArea absorbing the overflow.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(web): address review — align viewport units + drop stale subscriptions intent

Responding to the @claude review on #1479:

- Align all screen height calcs from `100vh` to `100dvh` so they match the
  Main slot's `100dvh` clamp. On a mobile viewport where `dvh < vh` a `100vh`
  child would have exceeded Main's `100dvh` content box and been clipped by
  `overflow: hidden`; the units are now in lockstep.
- Restrict `intendedButEmptySections` in ResourceControls to `allSections` so a
  stale "subscriptions" entry persisted from a prior subscription-capable
  session is dropped from persisted open-sections instead of being perpetually
  re-appended once the section is no longer rendered. Adds a regression test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/web/src/components/groups/ResourcePreviewPanel/ResourcePreviewPanel.tsx

@@ -24,6 +24,12 @@ export interface ResourcePreviewPanelProps {
   contents: (TextResourceContents | BlobResourceContents)[];
   lastUpdated?: Date;
   isSubscribed: boolean;
+  /**
+   * Whether the connected server advertises the `resources.subscribe`
+   * capability. When false, the Subscribe/Unsubscribe button is hidden.
+   * Defaults to true so the button renders unless explicitly unsupported.
+   */
+  subscriptionsSupported?: boolean;
   onRefresh: () => void;
   onSubscribe: () => void;
   onUnsubscribe: () => void;
@@ -168,6 +174,7 @@ export function ResourcePreviewPanel({
   contents,
   lastUpdated,
   isSubscribed,
+  subscriptionsSupported = true,
   onRefresh,
   onSubscribe,
   onUnsubscribe,
@@ -223,10 +230,12 @@ export function ResourcePreviewPanel({
           <Button variant="subtle" size="sm" onClick={onRefresh}>
             Refresh
           </Button>
-          <SubscribeButton
-            subscribed={isSubscribed}
-            onToggle={isSubscribed ? onUnsubscribe : onSubscribe}
-          />
+          {subscriptionsSupported && (
+            <SubscribeButton
+              subscribed={isSubscribed}
+              onToggle={isSubscribed ? onUnsubscribe : onSubscribe}
+            />
+          )}
         </ActionGroup>
       </FooterRow>
     </PanelStack>