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.

frontend/src/app/components/inventory-page/inventory-page.css

@@ -1,16 +1,16 @@
 .inventory-line {
-  margin: 1rem 0;
+	margin: 1rem 0;
 }
 .inventory-line label {
-  display: block;
-  margin: 0.5rem 0;
+	display: block;
+	margin: 0.5rem 0;
 }
 .inventory-line span {
-  display: block;
+	display: block;
 }
 .inventory-line input,
 .inventory-line select,
 .inventory-line textarea {
-  max-width: 32rem;
-  width: 100%;
+	max-width: 32rem;
+	width: 100%;
 }