Use one Geist tooltip in the web UI (#4272)

* Use one Geist tooltip across the web UI, workbench, and docs

The trace detail panel's "Navigate up"/"Navigate down" controls render the
Geist tooltip from packages/web-shared: a gray-1000 pill with a 10px radius,
2/1.5 padding, 13px label type, a triangular arrow, and an 8px side offset.
Three other tooltip implementations shipped alongside it and none of them
matched:

- packages/web had its own shadcn copy (light `bg-popover` surface, 1px
  border, `text-sm`, `rounded-md`, no portal, no arrow, 4px offset).
- workbench/nextjs-* had a newer shadcn copy (`bg-foreground`, `text-xs`,
  `rounded-md`, rotated-square arrow, 0px offset) plus per-call-site
  `bg-red-600`/`bg-orange-600` overrides.
- docs pulled `@vercel/geistdocs/components/tooltip` (`rounded-md`,
  `text-xs`, px-3, rotated-square arrow, 0px offset).

Now there is a single implementation:

- web-shared exports Tooltip/TooltipTrigger/TooltipContent/TooltipProvider
  and packages/web imports them, dropping its duplicate component.
- The workbench and docs each carry a verbatim copy of that component
  (they do not depend on web-shared). The workbench stylesheet gains the
  `--ds-gray-1000` / `--ds-background-100` tokens and the `text-label-13`
  utility the surface needs; docs already defines all three.
- docs mounts a TooltipProvider in GeistdocsProvider, since the shared
  Tooltip is the bare Radix root rather than a self-providing wrapper.

Call sites that fought the shared surface are cleaned up: the workbench
error-tooltip background overrides and the `text-xs` wrappers inside the
docs tooltip contents.

The tooltip arrow measures itself with ResizeObserver, which jsdom lacks,
so packages/web gains a vitest setup file that stubs it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Co-Authored-By: mitul-s <mitul-s@users.noreply.github.com>

* Scope the tooltip change to the web packages only

Drops the docs and workbench parts of this branch. The remaining change is
confined to `@workflow/web` and `@workflow/web-shared`: the shared Geist
tooltip is exported from web-shared and `packages/web` consumes it instead
of its own shadcn copy.

Reverted:

- docs — the local tooltip component, the TooltipProvider in
  GeistdocsProvider, the three worlds components re-pointed off
  `@vercel/geistdocs/components/tooltip`, the `@radix-ui/react-tooltip`
  dependency, and the lockfile entry it added.
- workbench/nextjs-* — the rewritten tooltip component, the Geist tokens and
  `text-label-13` utility added to globals.css, and the call-site cleanups in
  invocations-panel.tsx and ai-elements/message.tsx.

Those apps keep the tooltips they had on main.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Co-Authored-By: mitul-s <mitul-s@users.noreply.github.com>

* Stub ResizeObserver in the test instead of in the vitest config

Drops `packages/web/vitest.setup.ts` and reverts `vitest.config.ts`, so this
branch touches no test tooling configuration.

The shared tooltip renders an arrow, and Radix measures it with
ResizeObserver, which jsdom does not implement. Only status-badge.test.tsx
opens a tooltip, so the no-op stub now lives in that file.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Co-Authored-By: mitul-s <mitul-s@users.noreply.github.com>

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Co-authored-by: vercel[bot] <35613825+vercel[bot]@users.noreply.github.com>
Co-authored-by: mitul-s <mitul-s@users.noreply.github.com>