feat: archive a project instead of deleting it

The owner archives a finished project (archiveProject, POST
/projects/{project}/archive) and brings it back (unarchive). While
archived it stays readable, managers still read its rules and webhooks,
but no command changes it: contributing and managing checks refuse with
422, votes and public proposals too, and automations do not run. The web
shows a read-only notice on every page of it (with «Desarchivar» for the
owner), hides what edits, marks it on the home page and lists it last.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/api/tracker/application/src/lib/commands/command-handlers.ts

@@ -21,6 +21,7 @@ import { UpdateReleaseCommandHandler } from './update-release.command-handler';
 import { PublishReleaseCommandHandler } from './publish-release.command-handler';
 import { ArchiveReleaseCommandHandler } from './archive-release.command-handler';
 import { DeleteProjectCommandHandler } from './delete-project.command-handler';
+import { ArchiveProjectCommandHandler } from './archive-project.command-handler';
 import { DeleteIssueCommandHandler } from './delete-issue.command-handler';
 import { DeleteReleaseCommandHandler } from './delete-release.command-handler';
 import { PurgeCommentCommandHandler } from './purge-comment.command-handler';
@@ -66,6 +67,7 @@ export const COMMAND_HANDLERS = [
   PublishReleaseCommandHandler,
   ArchiveReleaseCommandHandler,
   DeleteProjectCommandHandler,
+  ArchiveProjectCommandHandler,
   // Emitted by sagas only (cascades and reactions to other aggregates).
   DeleteIssueCommandHandler,
   DeleteReleaseCommandHandler,