Update Python version requirements and fix compatibility issues

- Bump minimum Python version from 3.11 to 3.13 across all apps
- Add Python 3.11-3.13 test matrix to CLI workflow
- Document Python 3.11+ requirement in .env.example
- Fix Starlette Broadcast removal with in-process fallback implementation
- Add _InProcessBroadcast class for tests when Starlette Broadcast is unavailable
- Refactor API key validators to read live settings instead of cached values
- Update database models with explicit

gpu_acceleration_research/gpu_zk_research/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "gpu_zk_research"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+halo2 = { version = "0.1.0-beta.2" }
+halo2_proofs = { version = "0.1.0-beta.2" }
+halo2_gadgets = { version = "0.1.0-beta.2" }
+pasta_curves = "0.5"
+rand = "0.8"
+anyhow = "1.0"