Add interactive WebGL fractal explorer

[Copilot]

Adds a new standalone visual page (fractal.html) — a GPU-accelerated fractal explorer rendered entirely in GLSL fragment shaders with no external dependencies.

New: fractal.html

5 modes switchable via HUD:

Mode	Notes
Mandelbrot	Smooth cyclic coloring, 300-iteration escape
Julia	10 presets (Douady rabbit, Dendrite, San Marco…); double-click sets C
Burning Ship	Absolute-value iteration variant
Newton z³−1=0	3 attractor basins
Tricorn	Conjugate-squaring (Mandelbar)

Coloring uses cyclic banding (fract(smooth_i / 32.0)) through a 4-stop gradient matching the site palette exactly: #0a0a0f → #ff1d6c → #9c27b0 → #00bcd4.

Interactions: scroll-to-zoom toward cursor · drag to pan · double-click to zoom/set Julia C · pinch-to-zoom · keyboard 1–5 / R / J.

Navigation updates

• index.html footer — new ∞ FRACTAL EXPLORER link
• vr.html overlay — new ∞ Fractal Explorer → link

Screenshots

Mandelbrot	Julia — Douady rabbit	Newton z³−1=0

Original prompt

I really really like the html visuals can we add more

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[Copilot]

Copilot wasn't able to review any files in this pull request.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.