docs: fix typo

docs: replace 'live demo' with 'try it'

docs: update live demo URL to /LLMPlayground/

docs: update README with live demo link and new filename

refactor: rename LLMPlayground.html to index.html

feat: add index.html redirect to LLMPlayground.html

fix: security hardening — XSS prevention, CSP header, clickjacking protection

docs: update demo GIF

feat: UI fixes, updated demo GIF

docs: add demo GIF

refactor: group input sections under Prompt Builder

fix: preserve tool state in raw input after continuation

docs: add vibecoding toolchain to README

Initial commit: LLM Playground