A firefly-lit forest at dusk

Create a firefly-lit forest at dusk.

Fixed rules (so every model is compared on the same terms):
- Exactly one file, index.html, in the current directory. Create no other files.
- Use three.js 0.170.0 from https://cdn.jsdelivr.net/npm/three@0.170.0/ (via an import map; addons from examples/jsm are allowed). No other libraries, images, 3D models, fonts or network requests: build everything in the scene yourself in code.
- A full-window canvas that resizes with the window. No scrollbars, no text, no UI of any kind.
- A fixed camera: no orbit controls, and no user input needed.
- The scene plays on its own as a loop of about 12 seconds with a clear beginning, middle and return to the start, and keeps looping for as long as the page is open.
- Animate with requestAnimationFrame and its timestamp so the motion speed does not depend on the frame rate.

It must work in an ordinary browser on any graphics card. You cannot open a browser to look at it, so build it carefully:
- Every frame is fully drawn at every moment of the loop: no black, blank or flickering frames or patches. Keep shader maths free of NaN and infinity (no division by a value that can reach zero, no pow() of a negative number, no normalize() of a zero-length vector), and clamp colours to a safe range before bloom or other post-processing.
- The scene fills the whole window from the first frame.
- No errors in the browser console: map "three" and "three/addons/" in the import map, and import everything you use.
- It plays smoothly on an ordinary laptop or phone (keep the pixel ratio at 2 or below).

Everything else is your choice: the look, the setting, the lighting, colour, motion and detail. Make it as beautiful and lifelike as you can. Do not ask questions; make reasonable choices.