feat(web): migrate dashboard checkboxes to @nous-research/ui + DS polish (#28814)

* feat(web): migrate dashboard checkboxes to @nous-research/ui + DS polish

Replaces the hand-rolled shadcn-style `Checkbox` in `web/src/components/ui/`
with the Nous DS `Checkbox` (Radix-backed) from `@nous-research/ui`, bumps
the DS to 0.14.2, and picks up two regressions surfaced by the bump.

Checkbox migration
- bump `@nous-research/ui` 0.14.0 → ^0.14.2 and remove
  `web/src/components/ui/checkbox.tsx`
- migrate `ProfilesPage` and `ModelPickerDialog` to the DS Checkbox API
  (`onCheckedChange`, paired `<Label htmlFor>`)
- expose `Checkbox` on the dashboard plugin SDK
  (`web/src/plugins/registry.ts`) so plugin bundles can use the same
  DS component
- migrate the kanban dashboard plugin's 7 native `<input type="checkbox">`
  call sites to the SDK `Checkbox`, with a native-input fallback shim so
  the bundle still renders against older hosts that predate the SDK export

Fix: missing font registrations after the 0.14.x split
- import `@nous-research/ui/styles/fonts.css` before `globals.css` in
  `web/src/index.css`. As of 0.14.x, `globals.css` only declares the
  `--font-*` variables (Collapse, Mondwest, Rules Compressed/Expanded);
  the `@font-face` registrations now live in a separate `fonts.css`, so
  without this import the DS components silently fall back to a system
  font stack and look unstyled.

Fix: right-align page header toolbars on sm+ viewports
- The mobile dashboard polish in #28127 flipped four pages'
  `setEnd(...)` wrappers from `justify-end` to `w-full ... justify-start`
  so toolbars stack below the title and align left on small screens.
  But the outer `end` slot in `PageHeaderProvider` already has
  `sm:justify-end`, and that has no effect when its only child is
  `w-full` — once a flex child fills the row, the parent's `justify-*`
  can't move it. The toolbar pinned to the *left* of the right-side
  `sm:max-w-md` (~448px) slot, making the buttons appear to float a
  couple-hundred pixels off the right edge on Analytics, Models, Logs,
  and Plugins.
- Re-add `sm:justify-end` on the inner wrapper of each affected page,
  preserving the mobile stacked layout.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(nix): update web npmDeps hash for package-lock bump

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(nix): refresh npm lockfile hashes

* chore(ci): re-trigger checks after nix lockfile hash fix

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

web/src/plugins/registry.ts

@@ -21,6 +21,7 @@ import { api, fetchJSON } from "@/lib/api";
 import { cn, timeAgo, isoTimeAgo } from "@/lib/utils";
 import { Badge } from "@nous-research/ui/ui/components/badge";
 import { Button } from "@nous-research/ui/ui/components/button";
+import { Checkbox } from "@nous-research/ui/ui/components/checkbox";
 import { Select, SelectOption } from "@nous-research/ui/ui/components/select";
 import { Card, CardHeader, CardTitle, CardContent } from "@/components/ui/card";
 import { Input } from "@/components/ui/input";
@@ -121,7 +122,7 @@ export function exposePluginSDK() {
     // Raw fetchJSON for plugin-specific endpoints
     fetchJSON,
 
-    // UI components (shadcn/ui primitives)
+    // UI components — Nous DS where available, shadcn/ui primitives elsewhere.
     components: {
       Card,
       CardHeader,
@@ -129,6 +130,7 @@ export function exposePluginSDK() {
       CardContent,
       Badge,
       Button,
+      Checkbox,
       Input,
       Label,
       Select,