feat: add svelte5 support with source-shipping packaging

[meherhowji]

What this does

• Ships the raw .svelte source instead of a prebuilt file, so the same package works on both Svelte 4 and 5
• Fixes 4 Svelte 5 bugs that broke charts, including one where bind:chart wasn't ready in time, which broke the drill-down demo
• Adds TypeScript types (index.d.ts)
• Points all 33 Svelte 4 examples at the source
• Adds examples-v5/: a Vite + Svelte 5 app with 7 sample charts
• Bumps to v2.0.0, fixes the repo links and license to FusionCharts

Example fixes

• Two demos (fetch from JSON/XML URL) were loading a sample file that no longer exists (404). Moved them to the live CDN and set up CORS so the fetch works.
• Checked every chart in both apps in a real browser, all render, drill-down included
• Dropped the renderAt prop everywhere, it never actually did anything (the wrapper renders into its own div), so it was just confusing
• Used native Svelte 5 event syntax in the v5 samples (onclick instead of on:click)
• Small cleanups: fixed a support link that pointed at someone's old fork, updated the footer copyright, and removed a stale version note in the FusionTime section

Security

• No more Critical or High vulnerabilities anywhere in the repo. What I did:
  • Deleted a leftover root package-lock.json from the old build — it was flagging 3 High issues for packages we don't even use anymore
  • Bumped dompurify in the v5 example
  • Removed the unused serve dep from the v4 example and pinned uuid + http-proxy-middleware to safe versions
  • Started committing the v4 lockfile so the fixes stay put
• The only things left are 6 medium warnings on svelte@4.2.20. That's the last Svelte 4 ever released and the fixes only exist in Svelte 5, so there's nothing to upgrade to. They're dev-only and never ship to anyone. If it matters, the answer is just to use Svelte 5, which this package now supports.

Heads up (breaking change)

• The prebuilt index.js/index.mjs are gone. You now need a bundler that understands Svelte (basically any Svelte setup already does).

Still to do

• Tidy up the folder structure to something more modern (proper examples, lib, etc.)