refactor: enforce strict linting rules, replace forEach with for...of loops, and remove console logging throughout the frontend.

frontend/src/hooks/useAuth.ts

@@ -36,8 +36,7 @@ export const useAuth = () => {
   const logout = async () => {
     try {
       await api.post(endpoints.LOGOUT);
-    } catch (error) {
-      console.error("Logout failed:", error);
+    } catch (_error) {
     } finally {
       clearAuth();
       setMasterKey(null);

frontend/src/hooks/useLetters.tsx

@@ -43,8 +43,7 @@ async function decryptLetters(
         )) as LetterMetadata;
 
         return { ...letter, metadata };
-      } catch (err) {
-        console.warn("Decryption failed for letter:", letter.public_id, err);
+      } catch (_err) {
         return {
           ...letter,
           metadata: { recipient: "Encrypted Letter" },
@@ -67,7 +66,7 @@ export function useLetters() {
       .get(endpoints.LETTERS)
       .then((res) => decryptLetters(res.data, masterKey))
       .then(setLetters)
-      .catch((err) => console.error("Drawer load failed:", err))
+      .catch((_err) => {})
       .finally(() => setLoading(false));
   }, [masterKey]);