feat: dynamic fixedCollection inputs and output field hints (#9)

* feat: replace URL textarea with fixedCollection inputs and add output hints

- Replace single URL textarea with fixedCollection (row-based input UI)
  supporting compound scrapers (LinkedIn People Search, YouTube Comments)
- Add auto-generated inputSchemas.ts and outputSchemas.ts from monorepo
- Add NodeHint output field preview showing required + optional field counts
- Update all tests for new inputs.input fixedCollection parameter format

BREAKING CHANGE: Input parameter changes from `urls` (string) to
`inputs` (fixedCollection). Existing workflows need updating.

* build: add simple-icons dependency for icon generation

* feat: auto-generate platform SVG icons from Simple Icons

Add scripts/generate-icons.ts that pulls SVG paths from simple-icons
and writes light/dark variants to all node directories. Hardcodes
LinkedIn path (removed from Simple Icons v13+ due to trademark).

Yelp icons updated to latest Simple Icons path data.

Author: chiemerieokorie