feat/verifier nexus via ffi

[Oppen]

• docs: clarify risc0 version and installation (#1146)
• refactor(batcher): add user state & other code quality refactors (#1106)
• fix: operator downtime (#1073)
• chore: rm halo2 from verifiers (#1128)
• docs: add warning to use safe password for keystore (#1173)
• refactor(tracker): rewrite operator tracker in elixir (#1000)
• chore: Add explorer_create_env makefile target and update error messages. (#1121)
• fix: update package version in .toml to fix aligned --version (#1187)
• fix(batcher): Update Lambdaworks Merkle Trees + Update merkle leaves length check in batcher (#1067)
• add nexus verifier
• unneeded import
• docs + makefile
• remove compiled libs
• fix: use SliceData to avoid OOB access
• fix: typo in file name
• fix: more patching and feature enabling
• fix: larger incoming payloads for websockets
• fix: add Nexus prover to task sender
• chore: cargo.lock for Nexus
• fix: missing conflicts
• cargo.lock
• cargo fmt
• clippy
• fmt
• [wip] feat: integrate nexus ffi to the batcher