fix(tooltip): anchor above trigger with collision padding

The last row of the machines table opened tooltips below the trigger,
where they got clipped by the viewport — the page could scroll to
reveal them, but the popup was invisible on hover. Explicitly pin the
side to top and add 8px of collision padding so the Base UI flip logic
has enough room to keep the popup on-screen for last-row triggers.

Closes #508

Amp-Thread-ID: https://ampcode.com/threads/T-019e7ae4-6862-760c-a3e7-239350eab71d
Co-authored-by: Amp <amp@ampcode.com>

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Fixed user-management actions (link, change role, transfer ownership) using the wrong ID type for unlinked Headplane users. Form fields are now explicitly `headplane_user_id` vs `headscale_user_id`, and the auth layer no longer round-trips through Headscale to recover the OIDC subject.
 - Fixed dialog panels growing beyond the viewport; dialog content is now constrained and scrollable (via [#556](https://github.com/tale/headplane/pull/556)).
 - Fixed focus rings on inputs and buttons inside dialogs being clipped by the scrollable content container.
+- Fixed tooltips on the last row of the machines table being clipped by the viewport; tooltips now anchor above the trigger with collision padding (closes [#508](https://github.com/tale/headplane/issues/508)).
 - Corrected the Docker healthcheck example in the docs to use the required `CMD` prefix so reverse proxies don't see the container as unhealthy (closes [#535](https://github.com/tale/headplane/issues/535)).
 
 ---

app/components/tooltip.tsx

@@ -24,7 +24,7 @@ export default function Tooltip({ children, content, className }: TooltipProps)
         {children}
       </BaseTooltip.Trigger>
       <BaseTooltip.Portal>
-        <BaseTooltip.Positioner sideOffset={4}>
+        <BaseTooltip.Positioner side="top" sideOffset={4} collisionPadding={8}>
           <BaseTooltip.Popup
             className={cn(
               "z-50 rounded-lg p-3 text-sm w-48",