Fills the left pane of the modernized Overview with a paginated,
searchable activity list backed by static fixtures + a synthetic-latency
mock hook. Selection persists in the URL via `?selected=<id>` so refresh
keeps state. Right pane remains an empty-state card until the
backup-detail commit lands.

Adds `@wordpress/route` to the package root so the wordpress-externals
plugin can resolve it from `src/dashboard/screens/overview.tsx`; the
route sub-package already declared the same pin (mirrors Newsletter's
setup, where the dep is listed in both root and routes/dashboard).

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

Wires `?selected=<id>` to BackupDetail (status header + Download/Restore
actions + stats + files placeholder) for backup rows, and a lighter
ActivityDetail card for non-backup rows. Download/Restore actions
deep-link to `/download/$rewindId` and `/restore/$rewindId` which will
404 until the Restore + Download routes land in later commits.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Replaces BackupDetail's "Files placeholder" with a tree of folders +
files driven by useMockFileTree. Folders expand lazily with synthetic
latency so loading and empty states are exercised. Selecting a file
opens a side info-card with size, mime, path, and a monospace text
preview for text/PHP/SQL/CSS sources.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

New `/restore/$rewindId` wp-build route renders a narrow Restore form:
warning notice, six-item checklist (shared `<RestoreItemsChecklist>`),
Confirm button. Submission cycles through a synthetic state machine
(idle → submitting → progress → success), with a ~10% stochastic error
branch so the error UI is reachable during review.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Mirror of the Restore route minus the warning notice. The mocked submit
flow cycles idle → submitting → progress → success → mock download URL,
with the same ~10% stochastic error branch. Reuses the shared
`<RestoreItemsChecklist>` component.

This completes Phase 1: the modernized Backup dashboard now renders the
overview, file browser, restore, and download screens end-to-end with
mocked data. Real REST integration is a follow-up PR.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

- Wrap the Overview activity list in a Card.Root so the left pane
  picks up the same chrome (border, radius, background) as the right
  pane and the rest of the dashboard.
- Switch the activity list to `@wordpress/dataviews` (bundled) rather
  than `@wordpress/dataviews/wp` (script module), and pull the
  package's stylesheet into the dashboard route via
  `meta.load-css`. Without those styles the list-layout row button
  fell back to wp-admin's default button styling and rendered a
  visible 16x6 grey artifact in every row.
- Hide the redundant DataViews selection checkbox, center the media
  slot, keep the date/summary cell on a single line, and align the
  pagination footer pieces — same overrides Calypso's backup-overview
  list applies to DataViews.
- Restructure the backup detail card with explicit Card.Header /
  Card.Content slots so the header gets its bottom border separator
  and the body gets proper padding. Swap the restore icon back to
  rotateLeft to match the legacy admin.
- Lift the "FILES" section title into the detail card with its own
  top-border separator, and add a separator under the "N files
  selected" row.
- Add zebra striping to the file-browser tree with a literal hex —
  the --wp-components-color-gray-100 token is locally re-mapped to
  white inside Card.Content, which would defeat the alternation.
- Wrap the non-backup activity detail in Card.Content so it stops
  rendering flush against the card border.

Mocked data + flagged behaviour are unchanged; this is visual parity
work only.

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

The legacy "Backup" sidebar label doesn't match the modernized page
chassis (which already reads "VaultPress Backup") or the plugin's own
display name. Aligns the WP admin menu with the in-page title and the
product name used elsewhere.

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

Three related bugs in the modernized file-browser selection:

- Deselecting a row inside a selected subtree only added an exception
  but never propagated up. Now walks up: when every loaded child of an
  ancestor is effectively deselected, the ancestor is deselected too
  (and re-selecting reverses the same walk: when every loaded child
  becomes effectively selected, the ancestor follows). Stops at the
  first ancestor with un-loaded children.
- Indeterminate only fired for selected folders with a deselected
  descendant. Now symmetric: an unselected folder with a selected
  descendant also reads as indeterminate (e.g. visitor checks a single
  leaf without its ancestors).
- `applySelect` cleared an own-negative entry but didn't add an own
  positive, so re-checking a path whose ancestor stayed in `deselected`
  would silently inherit unchecked. Now: drop the negative and, only
  if removing it wouldn't already leave the row inherited-selected
  from an ancestor, add the explicit positive.
- The header "selected" count tracked `selected.size` (the explicit
  positives), which never grew as the visitor expanded an inherited
  subtree. Now hoists loaded folder children to the FileBrowser via a
  per-row callback and counts effectively-selected leaves only: a file
  counts as 1, a folder counts as 1 only when its contents haven't
  been loaded yet (otherwise the server treats it as one opaque
  download unit), and indeterminate folders contribute only the
  effectively-selected descendants underneath. BackupDetail reads the
  same count for its Download / Restore action labels via a new
  `onSelectionCountChange` callback, and the labels switch to proper
  singular/plural via `_n()`.

`useMockFileTree` no longer seeds non-null callers with the root tree
on first render — the seeding leaked the root tree into closed
NodeRows' `children` state and let the registerChildren effect
accidentally register MOCK_FILE_TREE for non-root paths during the
window between "open clicked" and "fetch resolved", which infinitely
recursed the count walk. FileBrowser now imports `MOCK_FILE_TREE`
directly for its roots; the hook handles only lazy non-root loads.

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

- The flag-gated `add-backup-modernization-dashboard-ui` entry uses
  `Comment:` only (no public `Entry:`), so `Significance: minor` was
  rejected ("Changelog entry may only be empty when Significance is
  'patch'"). Switch both the package and plugin entries to `patch`,
  matching the convention used by `update-backup-modernization-*` for
  gated, non-shipping work.
- Stylelint required a blank line before `@include` at the top of
  `body.jetpack_page_jetpack-backup { … }` in the modernized dashboard
  route stylesheet (at-rule-empty-line-before).

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

The Backup submenu entry's `page_title` changed from "Jetpack Backup"
to "Jetpack VaultPress Backup" (see the matching package commit), so
the array_search in `test_jetpack_admin_menu_order` needs the new
value to find the row's position.

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