feat: Migrate ESLint to flat config and resolve initial linting errors

Migrated the ESLint configuration to the new flat config format ()
and addressed several initial linting errors.

Key changes include:
- Updated ESLint configuration to treat  as warnings instead of errors.
- Fixed  errors in  by declaring  and .
- Corrected  error in  by using  instead of an out-of-scope .
- Resolved  error in  by replacing the undefined  directive with the  component.
- Addressed  errors in  by replacing  with  and  with .
- Fixed  errors in  by importing necessary modules (, , ) and adding missing props (, , , , ).

src/ae-osit-default.css

@@ -202,4 +202,4 @@
 	--color-surface-contrast-800: var(--color-surface-contrast-light);
 	--color-surface-contrast-900: var(--color-surface-contrast-light);
 	--color-surface-contrast-950: var(--color-surface-contrast-light);
-}
+}