[Feature] Implement debounced auto-save for resume form inputs

[knoxiboy]

Problem

The application currently triggers a direct localStorage write on every single keystroke. This causes excessive write cycles and performance lag in React rendering loops, especially when editing rich content areas.

Expected Behavior

Implement a custom debounce hook (useDebounce) so that localStorage sync triggers only after the user pauses typing for 500ms.

Target Files

• src/app/resume-builder/page.tsx
• Create a new hook in src/app/lib/hooks.ts or src/app/lib/useDebounce.ts

Suggested Steps

1. Create a useDebounce hook that wraps the saving state.
2. Modify the input handlers in the resume builder to update local state immediately (for visual responsiveness) but delay the serialization/storage routine until the debounce delay finishes.
3. Test by logging saves in dev mode to confirm it registers only one write per pause.

[knoxiboy]

/assign
Hi! @sunilkumar2170
I would like to work on this issue under GSSoC'26. Please assign this issue to me.