Phase 0+1: Repo-Skelett für Cards-Greenfield

Strategie B (beschlossen 2026-05-08): Cards wird als eigenständige
föderierte App neu gebaut, ohne Code-Übernahme aus mana-monorepo.

Skelett enthält:
- apps/api: Hono+Bun mit /healthz, /version, Manifest-Endpoint, leere
  pgSchema('cards'), Drizzle-Config, erstem Vitest
- apps/web: SvelteKit 2 + Svelte 5 (runes), Vite auf 3082
- packages/cards-domain: Pure-TS, CardType-Discriminated-Union,
  SubIndex-Granularität für Reviews, Future-CardType-Set vorbereitet
- infrastructure/docker-compose.yml: Postgres 16 auf 5435
- app-manifest.json: v1.0.0, Verein-owned, beta-tier
- .github/workflows/ci.yml
- docs/LESSONS_FROM_MANA_MONOREPO.md (Read-Day-Output, 15 Lehren)

Pre-Flight für Phase 2 (Auth-Föderation): DNS cardecky.mana.how,
GitHub-Repo mana-ev/cards, Cards-App-Registrierung in mana-auth,
NPM_AUTH_TOKEN für Verdaccio.

Plan: mana/docs/playbooks/CARDS_GREENFIELD.md

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -0,0 +1,46 @@
+name: CI
+
+on:
+    push:
+        branches: [main]
+    pull_request:
+        branches: [main]
+
+jobs:
+    validate:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v4
+
+            - name: Setup pnpm
+              uses: pnpm/action-setup@v4
+              with:
+                  version: 9.15.9
+
+            - name: Setup Node
+              uses: actions/setup-node@v4
+              with:
+                  node-version: 20
+                  cache: 'pnpm'
+
+            - name: Setup Bun (für apps/api)
+              uses: oven-sh/setup-bun@v2
+              with:
+                  bun-version: latest
+
+            - name: Install dependencies
+              run: pnpm install --frozen-lockfile
+              env:
+                  NPM_AUTH_TOKEN: ${{ secrets.NPM_AUTH_TOKEN }}
+
+            - name: Type-check
+              run: pnpm run type-check
+
+            - name: Test
+              run: pnpm run test
+
+            - name: Format check
+              run: pnpm run format:check
+
+            - name: Validate manifest
+              run: pnpm run validate:manifest