Closes the last TS-vs-Rust parity gap — the Rust shell lacked the
TS `component-browser-panel.tsx` (UIKit library browser +
click-to-instantiate).
- op-editor-core: `uikit.rs` with `UIKit` / `KitComponent` /
`ComponentCategory` types + a built-in starter kit (6 components
spanning button/input/card/nav/layout/feedback) as PenNode
templates; `EditorState::instantiate_kit_component` deep-clones
with fresh ids and translates the whole subtree to the drop point
(children carry document-absolute coords).
- op-editor-ui: `component_browser_panel.rs` floating draggable
panel — header (close), category pills (filtered to non-empty),
3-col card grid with name + scaled preview rect; kit-id + search
filters applied.
- op-host-native: paint at §11.5 (below the Design-MD panel),
`dispatch_component_browser_press`, drag lifecycle, shared
`over_topmost_panel` helper covers both top-most panels across
wheel / pan / right-press / cursor_hint / layer-hover / 4
overlay-hover blocks + align hover + stale-hover clear.
- op-host-desktop: View-menu toggle, `drain_component_browser_insert`
places at the viewport centre.
- op-editor-core: `active_children`/`active_children_mut` /
`ensure_pages` symmetric `pages: Some([])` fallback —
inserts land in `doc.children` and survive a subsequent
`add_page` (which migrates them into Page 1).
- op-i18n: new `componentBrowser.empty` × 15 locales.
Bumps vendor/jian for the rebased `DesignMdSpec` schema + the
`jian pack` designMd-filter for packaged apps.
1902d57807