feat: přidání testů – Jest unit testy + Playwright E2E + CI pipeline

Server:
- Jest unit testy (88 testů): auth, utils, restaurants, service, voting, pizza
- in-memory storage mock pro izolaci testů
- oprava race condition při inicializaci Redis (storageReady promise)
- dev route dostupná i pro NODE_ENV=test
- getStatsMock deterministický (nahrazení Math.random)
- exporty interních helperů pro testovatelnost
- /api/health endpoint pro Playwright readiness check
- tsconfig vylučuje test soubory z produkčního buildu

E2E (e2e/):
- Playwright s Firefoxem + Chromiem
- testy: login, menu, výběr jídla, pizza day životní cyklus, QR/nastavení
- trusted-header auth bypass pro testy, video + trace při selhání

CI (Woodpecker):
- pipeline spouštěna na všech větvích a PR (nejen master)
- redis-stack-server service pro E2E – čistý Redis per větev automaticky
- kroky: unit testy, build, E2E testy (parallel kde možné)
- Docker build zůstává pouze pro master

Co-Authored-By: Claude Opus (extra usage) 4.7 <noreply@anthropic.com>

.woodpecker/workflow.yaml

@@ -1,10 +1,18 @@
 variables:
   - &node_image "node:22-alpine"
+  - &playwright_image "mcr.microsoft.com/playwright:v1.59.1-jammy"
   - &branch "master"
 
+# Spustit na všech větvích a pull requestech.
+# Docker build probíhá jen na master větvi (viz when: v posledních krocích).
 when:
-  - event: push
-    branch: *branch
+  - event: [push, pull_request]
+
+services:
+  redis:
+    image: redis/redis-stack-server:7.2.0-RC3
+    environment:
+      REDIS_ARGS: "--save '' --loglevel warning"
 
 steps:
   - name: Generate TypeScript types
@@ -13,33 +21,81 @@ steps:
       - cd types
       - yarn install --frozen-lockfile
       - yarn openapi-ts
+
   - name: Install server dependencies
     image: *node_image
     commands:
       - cd server
       - yarn install --frozen-lockfile
     depends_on: [Generate TypeScript types]
+
   - name: Install client dependencies
     image: *node_image
     commands:
       - cd client
       - yarn install --frozen-lockfile
     depends_on: [Generate TypeScript types]
-  - name: Build server
+
+  - name: Install e2e dependencies
+    image: *playwright_image
+    commands:
+      - cd e2e
+      - yarn install --frozen-lockfile
+    depends_on: [Generate TypeScript types]
+
+  - name: Server unit tests
+    image: *node_image
+    environment:
+      NODE_ENV: test
+      JWT_SECRET: test-secret-min-32-chars-aaaaaaa!
+      MOCK_DATA: "true"
+      STORAGE: json
+    commands:
+      - cd server
+      - yarn test
     depends_on: [Install server dependencies]
+
+  - name: Build server
     image: *node_image
     commands:
       - cd server
       - yarn build
+    depends_on: [Install server dependencies]
+
   - name: Build client
-    depends_on: [Install client dependencies]
     image: *node_image
     commands:
       - cd client
       - yarn build
+    depends_on: [Install client dependencies]
+
+  - name: Playwright E2E tests
+    image: *playwright_image
+    environment:
+      CI: "true"
+      NODE_ENV: test
+      JWT_SECRET: test-secret-min-32-chars-aaaaaaa!
+      MOCK_DATA: "true"
+      STORAGE: redis
+      REDIS_HOST: redis
+      REDIS_PORT: "6379"
+      HTTP_REMOTE_USER_ENABLED: "true"
+      HTTP_REMOTE_USER_HEADER_NAME: remote-user
+      HTTP_REMOTE_TRUSTED_IPS: "0.0.0.0/0,::/0"
+    commands:
+      # Zkopírujeme build klienta do server/public, aby Express mohl SPA servírovat
+      - cp -r client/dist server/public
+      - cd e2e
+      - yarn playwright install firefox --with-deps
+      - yarn test
+    depends_on: [Build server, Build client, Install e2e dependencies]
+
   - name: Build Docker image
     depends_on: [Build server, Build client]
     image: woodpeckerci/plugin-docker-buildx
+    when:
+      - event: push
+        branch: *branch
     settings:
       dockerfile: Dockerfile-Woodpecker
       platforms: linux/amd64
@@ -51,11 +107,14 @@ steps:
         from_secret: REPO_PASSWORD
       repo:
         from_secret: REPO_NAME
+
   - name: Discord notification - build
     image: appleboy/drone-discord
     depends_on: [Build Docker image]
     when:
       - status: [success, failure]
+        event: push
+        branch: *branch
     settings:
       webhook_id:
         from_secret: DISCORD_WEBHOOK_ID