Vue and Svelte component detection

[BraedenBDev]

React component detection works by reading `__reactFiber$` properties from DOM nodes (see `src/content/react-inspector.ts`). We should extend this to other popular frameworks:

Vue:

• Vue 2 exposes `vue` on mounted DOM elements
• Vue 3 uses `vue_app` on the app root and `__vueParentComponent` on component elements
• Component name, props, and slots are accessible from the component instance

Svelte:

• Svelte components in dev mode attach `__svelte_meta` with the component filename and source location
• Svelte 5 (runes) may use different internals — needs investigation

Architecture:

• Each framework should have its own inspector file (`vue-inspector.ts`, `svelte-inspector.ts`) following the pattern in `react-inspector.ts`
• Framework detection should be opportunistic: try each detector, use whichever succeeds, fall back to a plain CSS selector if none match
• A selected element might be inside multiple frameworks (e.g., a Vue app with a React widget) — pick the most specific/innermost match
• The inspector interface should return: component name, props (serialized), file path (if available), and a human-readable component tree path

Help wanted — contributors who actively use Vue or Svelte would be especially helpful here, since testing requires real-world apps with dev mode enabled.