(CODUX-226) Translate project management - #3086

## Objective
Internationalize project management end to end, including globally reused project modals, without changing project API inputs or setup behavior.

## Scope
- Create `dashboard/src/v2/i18n/messages/projects.ts`
- Edit `dashboard/src/v2/ProjectsPage.tsx`
- Edit all files under `dashboard/src/v2/components/projects/`
- Edit `dashboard/src/v2/components/ui/AddProjectModal.tsx` and `NewProjectModal.tsx`
- Edit `dashboard/src/v2/lib/project-card-view-model.ts` and `projects-page-view-model.ts`
- Update project page, project-card, AddProjectModal, project setup, and E2E project tests

## Implementation Requirements
1. Translate page and card copy, creation modes, Git/local forms, directory controls, setup choices, progress, invocation status, validation, confirmation, empty states, and accessible announcements.
2. Use locale-aware date/number formatting for project metadata while retaining source paths, repository slugs, branches, project names, provider names, application-kind values, and API diagnostics verbatim.
3. Preserve creation payloads, background setup invocation, selection, navigation to Settings, deletion confirmation, duplicate-submit prevention, and stale-request handling.
4. Test German creation for local and Git projects, validation failures, setup progress/failure, selection, deletion, keyboard operation, mobile layout, and reuse of AddProjectModal from other routes.

## Constraints
- Do not edit `dashboard/src/main.tsx`, TopNav, Tasks, or Sprints callers; they receive the translated modal after integration.
- Do not change project settings contracts, API routes, filesystem validation, or setup execution.
- Do not translate user-entered names, paths, repository identifiers, or provider/runtime error messages.

## Verification
- Run focused project page, project-card, AddProjectModal, and project-data tests.
- Run `pnpm run lint`.
- Run `pnpm run test:dashboard`.
- Run `pnpm run build`.
- Success means all project workflows are operable in German and submitted project/setup payloads remain unchanged.