Enhancement: Upgrade Coil to 3.x

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Summary

The project uses Coil 2.5.0 (io.coil-kt:coil-compose). Coil 3.0 is now stable and is a major version bump with breaking changes that also bring significant improvements.

Key Changes in Coil 3

• Multiplatform support — Coil 3 supports Kotlin Multiplatform (KMP), enabling future Desktop/Web targets.
• Improved performance — Faster image loading and better memory management.
• New artifact group: io.coil-kt.coil3:coil-compose (note the coil3 group ID).
• OkHttp is now optional: Coil 3 uses Ktor or OkHttp interchangeably; coil-network-okhttp sub-artifact needed to keep OkHttp.
• Breaking API changes: AsyncImage API is largely the same but ImageLoader configuration has changed.

Proposed Changes

1. In Versions.kt, update:

   const val coilCompose = "3.x.x"  // e.g. "3.1.0"

2. In Dependencies.kt, update the artifact group:

   const val coilCompose = "io.coil-kt.coil3:coil-compose:${Versions.coilCompose}"
   const val coilNetworkOkHttp = "io.coil-kt.coil3:coil-network-okhttp:${Versions.coilCompose}"

3. Add coilNetworkOkHttp to GroupedDependencies.kt alongside coilCompose.
4. Update any call sites that use deprecated Coil 2 APIs.
5. Ensure all demo screens that load images (Instagram, Movies, Crypto, etc.) still function correctly.

References

• Coil 3 Migration Guide
• Coil 3 GitHub Releases