test(web): re-anchor snapshot suites to the startup-selection boot flow

The startup Workspace auto-selection (wired in cd8ed43e4) changed the
boot landing: with any Workspace present the client connects its blank
session directly instead of resting in the locked view state.

- workspace-flow: New Session now reuses the blank session in place
  (no locked interlude); the failed-attach scenario asserts the actual
  recovery semantics — the host publishes the session before rejecting
  attachment, so the next connect reuses it into the hero (connect
  failures log to console, there is no view-state alert surface); the
  rejected-prompt scenario anchors on the sidebar New Session row since
  a send attempt leaves the hero for the engaging retry chrome.
- slash-flow: drop the stale i18n PLUGINS row (the package is locale).

apps/web/tests/slash-flow.snapshot.ts

@@ -20,7 +20,6 @@ const PLUGINS: readonly (WebBootEntry & { dir: string })[] = [
   { id: '@deepseek-ai/dsh-client-connection', dir: 'connection', url: '/plugins/connection.js', rev: 'fx', inject: [], immediately: true },
   { id: '@deepseek-ai/dsh-client-runtime', dir: 'runtime', url: '/plugins/runtime.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-connection'], immediately: true },
   { id: '@deepseek-ai/dsh-client-ui-theme', dir: 'ui-theme', url: '/plugins/ui-theme.js', rev: 'fx', inject: [], immediately: true },
-  { id: '@deepseek-ai/dsh-client-i18n', dir: 'i18n', url: '/plugins/i18n.js', rev: 'fx', inject: [], immediately: true },
   { id: '@deepseek-ai/dsh-client-locale', dir: 'locale', url: '/plugins/locale.js', rev: 'fx', inject: [], immediately: true },
   { id: '@deepseek-ai/dsh-client-ui-layout', dir: 'ui-layout', url: '/plugins/ui-layout.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-runtime'] },
   { id: '@deepseek-ai/dsh-client-ui-sidebar', dir: 'ui-sidebar', url: '/plugins/ui-sidebar.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-layout'] },