fix: rewrite GitHub Pages site to display properly with dynamic OSINT detective humor (#129)

The site at thumpersecure.github.io/Spin was showing the README.md
rendered by Jekyll instead of the OSINT toolkit HTML. Root causes:
- No index.html at repo root (Pages served README as fallback)
- No .nojekyll file to prevent Jekyll processing

Changes:
- Add .nojekyll at root and docs/ to bypass Jekyll
- Add index.html, style.css, app.js at repo root so Pages serves them
- Completely rewrite all three files with cleaner, well-structured code
- Add animated loading screen with investigator boot sequence
- Add rotating OSINT detective jokes system (24 jokes)
- Add scrolling intel brief ticker with 20 OSINT tips
- Add periodic "Field Note" tip popups
- Add rotating header taglines and footer jokes
- Add case number generator and session ID
- Add classified stamp, scanline overlay, gradient animations
- Add investigation status panel with OPSEC level meter
- Preserve all existing OSINT tools (phone, email, username, domain,
  entity extractor, hivemind, bookmarks)
- Sync all files to docs/ folder as well

Author: thumpersecure