feat(ui-react): implement announcements admin panel

[luizhf42]

What

Full CRUD for system-wide announcements in the React admin panel — list with pagination, detail view, create page, edit page, and delete confirmation. Content is authored with a Tiptap v3 rich text editor and stored as markdown on the backend.

Why

Feature #10 from shellhub-io/team#93. The announcements feature existed only in the Vue admin panel and needed to be ported to the React console.

Changes

• Routing: Four lazy-loaded routes under /admin/announcements, conditionally registered when getConfig().announcements is enabled. Routes are inside AdminRoute > LicenseGuard, so they inherit admin auth and license checks. Direct URL access returns 404 when the feature flag is off.
• Data hooks: useAdminAnnouncements (paginated list + single entity) and useAdminAnnouncementMutations (create, update, delete with query invalidation). Follow the exact patterns from useAdminNamespaces and useAdminNamespaceMutations.
• Rich text editor: Tiptap v3 with @tiptap/markdown for native bidirectional markdown support — eliminates the Vue codebase's Turndown + MarkdownIt conversion pipeline. Toolbar with bold, italic, strike, headings, lists, blockquote, code blocks, links, images, undo/redo. Includes roving tabindex for keyboard navigation.
• Security: isAllowedUrl utility (extracted to utils/url.ts) validates link/image URLs against an allowlist (http:, https:, mailto:) in both the editor toolbar prompts and the Link extension's validate option (covers paste/auto-detect). The read-only renderer adds rel="noopener noreferrer" and target="_blank" to rendered links.
• Read-only renderer: AnnouncementContent uses a non-editable Tiptap instance with the same extensions as the editor, guaranteeing visual parity. Parent passes key={uuid} to force re-mount on content changes.
• List page: Paginated table with UUID chip, title, date, and action buttons (edit navigates, delete opens dialog). Auto-resets to last valid page after deleting the final item on a non-first page.
• Create/Edit pages: Full-page forms wrapped in <form> for Enter-key submission. Title field with live character counter (max 90). Edit page uses null state to distinguish "not yet edited" from "cleared", avoiding overwrites on query refetch.
• Tests: 47 unit tests covering the list page (rendering, loading/empty/error states, navigation, pagination, delete action) and the delete dialog (confirmation flow, error handling, callback order, null announcement guard).

Testing

• Enable the announcements feature flag in the dev environment config
• Create an announcement with rich text (headings, lists, links, images by URL), verify it stores and renders correctly
• Edit an existing announcement, verify title and content update without losing formatting
• Delete from both the list page and detail page
• Test with the feature flag disabled — /admin/announcements should 404, sidebar link should be hidden
• Verify keyboard navigation through the editor toolbar (Tab enters, arrow keys cycle, Tab exits)

[github-actions]

Claude finished @luizhf42's task in 5m 22s —— View job

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Code Review Complete

Reviewed 16 files across code quality, security, testing, TypeScript/React patterns, and architecture. 1 inline issue posted (medium severity — URL validation bug).

The overall implementation is solid: routing is correctly nested under AdminRoute > LicenseGuard with feature-flag gating, hooks follow established patterns (useAdminNamespaces/useAdminNamespaceMutations), the rich-text editor has good accessibility (roving tabindex, ARIA attributes), and the 47 unit tests provide thorough coverage of the list page and delete dialog. No pkg/ changes, so no cross-repo impact on cloud/enterprise.

If you've addressed the feedback and want a new review, tag @shellhub-io/admin and a team member can trigger it.

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[gustavosbarreto]

/review

[github-actions]

Claude finished @gustavosbarreto's task in 1m 40s —— View job

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Code Review Complete

Reviewed 16 files across code quality, security, testing, TypeScript/React patterns, and architecture. 1 inline issue posted (high severity — stale editor content on same-route navigation).

The overall implementation is solid: routing is correctly nested under AdminRoute > LicenseGuard with feature-flag gating, hooks follow established patterns (useAdminNamespaces/useAdminNamespaceMutations), the Tiptap editor has good accessibility (roving tabindex, ARIA attributes), URL validation correctly blocks dangerous protocols, and the 47 unit tests provide thorough coverage. No pkg/ changes, so no cross-repo impact on cloud/enterprise.

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If you've addressed the feedback and want a new review, tag @shellhub-io/admin and a team member can trigger it.