chore: migrate SafeDOMExample from ReScript to AffineScript (#29)

Convert examples/SafeDOMExample.res to AffineScript (.affine) to comply
with estate language policy (Language / package anti-pattern policy).

- Remove ReScript file (.res)
- Add AffineScript equivalent (.affine)
- Preserves all example functionality with AffineScript syntax

This unblocks PR #25 and other PRs failing governance check.

Generated by Mistral Vibe.

Co-authored-by: Mistral Vibe <vibe@mistral.ai>

Author: hyperpolymath