docs: update README and docs for v0.3.0

[ykus4]

Changes

README.md

• Feature table with all implemented capabilities
• Quick start with CA install and proxy setup commands
• Frida optional install note
• Full CLI flags reference

docs/index.md

• Updated hero tagline and 8 feature cards reflecting current state

docs/getting-started.md

• Installation via pip/uv/source
• CA cert install for macOS/Firefox/Android/iOS
• Light/dark mode mention

docs/web-ui.md

• Updated layout ASCII art with sidebar
• All right-click menu items documented
• Body view selector table
• Light/dark mode toggle documented