Two cohesive cleanups in one pass; both are pure surface-level (no
behavior or layout changes), and both unblock the larger pane-level
refactors that come next.

## New primitive: StatusDot

`desktop/src/components/ui/status-dot.tsx` — small colored dot
indicating a state (running, error, working, etc.). Replaces ~14
hand-rolled `<span className="size-X rounded-full bg-X" />` instances
across the shell so a single change here propagates everywhere.

cva-based variants matching real usage:
- `variant`: success | destructive | warning | info | primary | muted | neutral
- `size`: sm (6px, default) | md (8px) | lg (10px)
- `withRing`: card-colored ring for badge dots that sit on top of icons
- `pulse`: enables animate-pulse for "in progress" / "starting" states

Sites swapped: AppSurfacePane, IntegrationsList, ConnectIntegrationsStep,
PublishScreen, SpaceBrowserDisplayPane, SpaceApplicationsExplorerPane,
SpaceBrowserExplorerPane (5 sites), OperationsDrawer (badge dot,
withRing + lg), ChatPane (inbox-unread badge), RuntimeStatusIndicator
(refactored visual spec to carry `dotVariant` + `dotPulse` instead of
a Tailwind class string), AuthPanel, CreatingView.

## Token cleanup

Eliminate hand-rolled opacity hacks on canonical tokens — these were
masking earlier insufficient-contrast palettes that the current design
system has since resolved at the token level.

- `border-border/35|40|55|60|70` → `border-border` (28 occurrences across 13 files)
- `bg-foreground/6` → `bg-fg-6`; `bg-foreground/5` → `bg-fg-5`
- The dropdown-menu / select shadcn templates keep their
  `bg-foreground/10` because those live inside `**:data-[state=...]`
  variant selectors that need a literal token.

Magic-number radii mapped to the standard scale:

| Hand-rolled | Mapped to |
|---|---|
| `rounded-[7px]`  | `rounded-md` |
| `rounded-[10px]` | `rounded-lg` |
| `rounded-[12px]` | `rounded-xl` |
| `rounded-[14px]` | `rounded-2xl` |
| `rounded-[16px]` | `rounded-2xl` |
| `rounded-[18px]` | `rounded-2xl` |
| `rounded-[20px]` | `rounded-2xl` |
| `rounded-[22px]` | `rounded-2xl` |
| `rounded-[24px]` | `rounded-3xl` |
| `rounded-[28px]` | `rounded-3xl` |
| `rounded-[4px]`  | `rounded-sm` |
| `rounded-[9999px]` | `rounded-full` |

The 18/20/28 → 2xl/3xl mappings shrink the affected dialog/sheet
shells by 2-4px on a single visual element. Small enough to be
imperceptible side-by-side but consolidates the radius scale to
shadcn standards. Two intentional pixel-level decorations stay
hand-tuned: the tooltip arrow corner (rounded-[2px]) and the chat
streaming-cursor block (rounded-[1px]).

## Verification

- `npm run desktop:typecheck` — clean
- `npm --prefix desktop run build:renderer` — clean
- `node --test` on AppShell + SpaceApplicationsExplorerPane — same
  pass count as upstream/main baseline (49 pass / 1 pre-existing
  fail on an unrelated `updateNotification` brittle assertion).

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

The dashboard's `EmptyState` was a great primitive locked in the wrong
folder. Five other surfaces hand-rolled the same pattern (sidebar
empties, automations placeholders, publish-wizard docs empties,
marketplace gallery empties), each with subtly different copy
hierarchy and chip treatments.

This PR moves `EmptyState` to `desktop/src/components/ui/`, extends
its API, and migrates the hand-rolled call sites.

## API

```tsx
<EmptyState
  icon={Icon}                 // optional LucideIcon
  title="No items"            // primary line (was `message`)
  description="Sub line"      // optional secondary (was `hint`)
  action={<Button…/>}         // optional CTA below
  size="sm" | "md"            // sm = compact dashboard look (default),
                              // md = chip-icon + text-sm + roomier padding
  minHeight={number}          // forces height (chart panels)
  className=""                // outer wrapper extras
/>
```

`sm` keeps the original dashboard visual (small unframed icon at
opacity-45, text-xs message). `md` wraps the icon in a muted chip and
uses text-sm/text-xs for title/description — the look that
SpaceApplicationsExplorerPane, SpaceBrowserExplorerPane, and
AutomationsPane were rolling by hand.

## Migrations

- **dashboard/{Board,Table,List,Chart}** (4 sites): import path moved,
  `message` → `title`, `hint` → `description`. Visual unchanged.
- **AutomationsPane**: deleted local 21-line `EmptyState` + 30-line
  `EmptyScheduled` re-implementations. The CTA "Ask the agent" now
  uses the new `action` slot.
- **SpaceApplicationsExplorerPane** + **SpaceBrowserExplorerPane**:
  inline chip-icon empty states swapped for `<EmptyState size="md" />`.
- **publish/LivePreviewPanel**: deleted local 8-line `DocsEmptyState`,
  swapped its 2 call sites.
- **marketplace/AppsGallery**: the "No apps available." and "No apps
  match the current filter." inline divs become real EmptyStates.
  Filter empty surfaces a Search icon + the existing Clear-filter CTA
  via the new `action` slot.
- **marketplace/MarketplaceGallery**: same treatment — Search icon for
  filter empty, LayoutGrid for the "no templates yet" case.

## Deliberately not migrated

- **OperationsDrawer.EmptyNotice**: 5 call sites use it for spinner +
  error states, not just empty. Different semantic; primitive doesn't
  cover it cleanly.
- **InternalSurfacePane.EmptyState**: framed bordered card with
  tone="error" variant for file-preview failures. Also different —
  it's a "preview frame", not a placeholder.
- **BackgroundTasksPane** + **SubagentSessionsPane**: dashed-border
  containers with single-line text. Intentionally different visual
  (placeholder zone, not centered empty state).

## Verification

- `npm run desktop:typecheck` — clean
- `npm --prefix desktop run build:renderer` — clean

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