[GSSoC26] feat: Add "Last Auto-Saved" timestamp indicator to resume builder

[sanjam3712]

Hi @sunilkumar2170 ! 👋

I am participating in GSSoC '26 and have been exploring the project. I noticed a small but reassuring improvement for users!

📌 Feature Request

Problem
The resume builder already auto-saves data to localStorage, but users have no way of knowing when their data was last saved. This creates anxiety - "Did my changes get saved? Will I lose my work?"

Proposed Solution
Add a small "Last saved: X minutes ago" timestamp indicator at the bottom of the resume form that:

• Shows the exact time data was last saved to localStorage
• Updates automatically every time a change is made
• Displays in a friendly relative format:
  • "Last saved: just now"
  • "Last saved: 2 minutes ago"
  • "Last saved: 5 minutes ago"

Expected Behavior

• Indicator appears at the bottom of the left form panel
• Updates in real time as user types
• Shows "Saving..." briefly before confirming "Last saved: just now"
• Subtle and unobtrusive - small gray text

Benefits

• Reduces user anxiety about losing resume data
• Makes the auto-save feature visible and trustworthy
• Improves overall user experience
• Common pattern used by Google Docs, Notion, and other editors

Implementation

• Frontend-only change using React useState and useEffect
• Hooks into the existing localStorage save mechanism
• No backend changes needed

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Could you please assign this issue to me if approved? I would love to work on this! 🙌