Chore: Resolve Deprecated Packages (Recharts v3, ESLint v9, Next-PWA)

[ArshVermaGit]

Description

This PR eliminates the massive wall of deprecation warnings (inflight, rollup-plugin-terser, recharts, eslint) that were clogging up the npm install logs and introducing future technical debt.

Resolved Issue

Resolves #1539

Fixes:

• 📈 Recharts Migration: Upgraded from ^2.12.7 to ^3.8.1. This removes legacy React 17 dependencies (like defaultProps) and improves SSR compatibility.
• ⚙️ Next PWA Fork: The original next-pwa package is dead. Replaced it with the community-maintained @ducanh2912/next-pwa drop-in replacement, which purges the deprecated rollup-plugin-terser sub-dependency.
• 🧹 ESLint Flat Config: Upgraded ESLint to ^9.0.0 and migrated the legacy .eslintrc.json to the modern Flat Config (eslint.config.mjs). Also cleaned up several unused eslint-disable comments across the codebase.
• 🚀 SSR Optimization: Removed { ssr: false } from our dynamic chart imports in DashboardPage, allowing Next.js 15 to properly render the skeleton loaders on the server.

Breaking Changes / Follow-ups Needed

The major version bumps to Next.js 15 and Recharts v3 introduced a few strict TypeScript errors that currently fail the npm run build step (e.g., req.ip was removed from NextRequest, and Recharts Tooltip generic types have changed). These will need to be patched before this can be deployed.

How to Verify

1. Pull down this branch.
2. Run npm install and verify the output is perfectly clean (0 deprecation warnings).
3. Run npm run lint and verify there are no ESLint errors.
4. Run npm run test to verify the unit test suite still passes.

[vercel]

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[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus

[ArshVermaGit]

Hi @Priyanshu-byte-coder ! Issue #1539 has been resolved. Please review the PR and merge it under GSSoC. Thanks!

[Priyanshu-byte-coder]

This PR now has merge conflicts with main due to recent merges. Please rebase onto the latest main branch and resolve conflicts before we can merge.

[ArshVermaGit]

This PR now has merge conflicts with main due to recent merges. Please rebase onto the latest main branch and resolve conflicts before we can merge.

Done Please review!

[Priyanshu-byte-coder]

This PR now has merge conflicts with main. Please rebase your branch against the latest main and force-push to resolve. Run: git fetch upstream && git rebase upstream/main

[ArshVermaGit]

@Priyanshu-byte-coder merge conflicts are resolved please review and merge

[Priyanshu-byte-coder]

This PR has merge conflicts with the current main branch. Please rebase your branch onto main, resolve the conflicts, and force-push. Once conflicts are resolved and the PR is marked as mergeable it will be reviewed for merging.

[gitguardian]

⚠️ GitGuardian has uncovered 3 secrets following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

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🔎 Detected hardcoded secrets in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
33523564	Triggered	Generic High Entropy Secret	29bddf6	.env.example	View secret
33523565	Triggered	Supabase Service Role JWT	29bddf6	.env.example	View secret
33523566	Triggered	JSON Web Token	29bddf6	.env.example	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
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To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

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[Priyanshu-byte-coder]

Closing — this PR accidentally includes Python automation scripts (fix_goaltracker.py, fix_header.py, fix_script.py, fix_ts.py, etc.) that should not be committed to the repository. Please remove these files, and also update the PR description — the Recharts v3 migration is a large change that should be validated against the current main branch before merging.