Feature Proposal: Add 3D Parallax Effect to Gallery Viewer (iOS 26 "Spatial Scenes" style)

[klnn567]

1. Is your feature request related to a problem? Please describe.
   Currently, Refra's gallery viewer displays images statically. On Android, there is no native support for 3D parallax interactions like iOS 26's "Spatial Scenes", which makes the viewing experience less immersive compared to Apple's ecosystem. Since Refra is designed as an offline‑first, privacy‑focused gallery app, any solution should work without network dependencies.

2. Describe the solution you'd like
   I propose adding a dynamic 3D parallax effect to the image viewer, driven by local depth map estimation. When users tilt their device or swipe, the image responds with subtle perspective shifts, creating a spatial feel. All processing must stay on‑device to preserve privacy.

3. Additional context
   I came across two lightweight depth estimation resources that are suitable for offline use:

• https://serverless.tools/zh/shendutu-shengcheng/ – A web tool that bundles a ~35MB depth model; it caches the model locally on first visit and works fully offline afterward. The effect is quite good.
• https://github.com/gengyj16/DepthWeaver – Another interesting GitHub project that provides lightweight depth map generation.

Given Refra's core mission of offline, privacy‑secure gallery management, a self‑contained depth estimation approach aligns perfectly. Such a feature is still rare on Android, and I believe it would make Refra stand out.

I understand this may involve significant engineering effort, so I'll leave the feasibility and priority to your judgment. I'm just a regular user sharing this idea for your consideration. Thanks for reading!