[Pcmhacker-hero]

Resolves #9377

Changes:
- **`src/strands/strands_for.js`**: When updating loop-carried variables and helper states at the end of an iteration (and on `break`), detect whether any update's source expression reads a target phi variable assigned by another
update in the set.
  - If inter-dependencies exist (such as variable swaps, rotations, or Fibonacci-style recurrences), allocate temporary phi variables in the loop's `branchBlock`.
  - In the target block (e.g. `finalBodyBlock`), update the loop state in two distinct phases: first evaluate and buffer the new values into the temporaries, then assign the temporaries into their target phi nodes.
  - If no inter-dependencies exist between the loop-carried variables, preserve direct assignments to the target phi nodes without overhead.
- **Unit Tests (`test/unit/webgl/p5.Shader.js`, `test/unit/webgpu/p5.Shader.js`)**: Added regression unit tests reproducing the swap issue reported in #9377 as well as Fibonacci-style sequential updates across iterations, verifying
correct evaluation in both WebGL and WebGPU.

#### PR Checklist

- [x] `npm run lint` passes
- [ ] [Inline reference] is included / updated
- [x] [Unit tests] are included / updated

[Pcmhacker-hero]

Hi @davepagurek @limzykenneth! 👋

Could you please review this PR when you have a moment?

It resolves #9377 by ensuring that loop-carried variables and helper states with inter-dependencies (e.g. variable swaps, coordinate rotations, or Fibonacci-style recurrences) are buffered through temporary phi variables before
updating target phi nodes. This prevents earlier assignments from overwriting values read later in the same iteration.

- Implemented in `src/strands/strands_for.js` with dependency detection so loops without inter-dependencies maintain direct assignments.
- Added regression tests in both WebGL (`test/unit/webgl/p5.Shader.js`) and WebGPU (`test/unit/webgpu/p5.Shader.js`).
- All 225 `p5.strands` tests pass, and `npm run lint` passes with 0 errors.

Thank you!