chore: add husky pre-commit hook and lint-staged configuration

- Created a pre-commit hook in .husky to run lint-staged.
- Added .lintstagedrc.mjs to format frontend files with Prettier and apply Spotless to backend Java files.
- Introduced .prettierignore to exclude specific directories from formatting.

.gitlab-ci.yml

@@ -1,79 +1,79 @@
 stages:
-  - test
-  - publish
+    - test
+    - publish
 
 workflow:
-  rules:
-    - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
-    - if: '$CI_COMMIT_TAG'
-    - if: '$CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS && $CI_PIPELINE_SOURCE == "push"'
-      when: never
-    - if: '$CI_COMMIT_BRANCH'
+    rules:
+        - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
+        - if: '$CI_COMMIT_TAG'
+        - if: '$CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS && $CI_PIPELINE_SOURCE == "push"'
+          when: never
+        - if: '$CI_COMMIT_BRANCH'
 
 backend-test:
-  stage: test
-  image: maven:3.9-eclipse-temurin-25-alpine
-  interruptible: true
-  script:
-    - cd backend
-    - mvn clean verify
+    stage: test
+    image: maven:3.9-eclipse-temurin-25-alpine
+    interruptible: true
+    script:
+        - cd backend
+        - mvn clean verify
 
 frontend-test:
-  stage: test
-  image: node:26-alpine
-  interruptible: true
-  script:
-    - npm install -g bun
-    - cd frontend
-    - bun install --frozen-lockfile
-    - bun run lint
-    - bun run typecheck
-    - bun run test --coverage --watch=false
+    stage: test
+    image: node:26-alpine
+    interruptible: true
+    script:
+        - npm install -g bun
+        - cd frontend
+        - bun install --frozen-lockfile
+        - bun run lint
+        - bun run typecheck
+        - bun run test --coverage --watch=false
 
 frontend-e2e:
-  stage: test
-  image: mcr.microsoft.com/playwright:v1.61.1-noble
-  interruptible: true
-  script:
-    - npm install -g bun
-    - cd frontend
-    - bun install --frozen-lockfile
-    - bun run e2e
+    stage: test
+    image: mcr.microsoft.com/playwright:v1.61.1-noble
+    interruptible: true
+    script:
+        - npm install -g bun
+        - cd frontend
+        - bun install --frozen-lockfile
+        - bun run e2e
 
 .publish-image:
-  stage: publish
-  image: quay.io/buildah/stable:latest
-  variables:
-    STORAGE_DRIVER: vfs
-    BUILDAH_FORMAT: docker
-  before_script:
-    - echo "$CI_REGISTRY_PASSWORD" | buildah login --username "$CI_REGISTRY_USER" --password-stdin "$CI_REGISTRY"
-  script:
-    - |
-      if [ -n "$CI_COMMIT_TAG" ]; then
-        IMAGE_TAG="$CI_COMMIT_REF_SLUG"
-      else
-        IMAGE_TAG="latest"
-      fi
-      buildah build \
-        --pull-always \
-        --tag "$IMAGE_NAME:$CI_COMMIT_SHA" \
-        --tag "$IMAGE_NAME:$IMAGE_TAG" \
-        "$BUILD_CONTEXT"
-      buildah push "$IMAGE_NAME:$CI_COMMIT_SHA"
-      buildah push "$IMAGE_NAME:$IMAGE_TAG"
-  rules:
-    - if: '$CI_COMMIT_TAG'
-    - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'
+    stage: publish
+    image: quay.io/buildah/stable:latest
+    variables:
+        STORAGE_DRIVER: vfs
+        BUILDAH_FORMAT: docker
+    before_script:
+        - echo "$CI_REGISTRY_PASSWORD" | buildah login --username "$CI_REGISTRY_USER" --password-stdin "$CI_REGISTRY"
+    script:
+        - |
+            if [ -n "$CI_COMMIT_TAG" ]; then
+              IMAGE_TAG="$CI_COMMIT_REF_SLUG"
+            else
+              IMAGE_TAG="latest"
+            fi
+            buildah build \
+              --pull-always \
+              --tag "$IMAGE_NAME:$CI_COMMIT_SHA" \
+              --tag "$IMAGE_NAME:$IMAGE_TAG" \
+              "$BUILD_CONTEXT"
+            buildah push "$IMAGE_NAME:$CI_COMMIT_SHA"
+            buildah push "$IMAGE_NAME:$IMAGE_TAG"
+    rules:
+        - if: '$CI_COMMIT_TAG'
+        - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'
 
 publish-backend-image:
-  extends: .publish-image
-  variables:
-    IMAGE_NAME: "$CI_REGISTRY_IMAGE/backend"
-    BUILD_CONTEXT: backend
+    extends: .publish-image
+    variables:
+        IMAGE_NAME: '$CI_REGISTRY_IMAGE/backend'
+        BUILD_CONTEXT: backend
 
 publish-frontend-image:
-  extends: .publish-image
-  variables:
-    IMAGE_NAME: "$CI_REGISTRY_IMAGE/frontend"
-    BUILD_CONTEXT: frontend
+    extends: .publish-image
+    variables:
+        IMAGE_NAME: '$CI_REGISTRY_IMAGE/frontend'
+        BUILD_CONTEXT: frontend