Release v0.5.2

[fedgiac]

Includes all changes that should be audited. This will be an in-place upgrade.
I bumped to v0.5.2 to respect the versioned "ghost" staging deployment, #197, which deployed the staging program. We should come up with a better mechanism for staging.
The staging program has already been updated.

Staging update

 just deploy "$PROGRAM_ID" "$DEPLOYER_KEYFILE"
cargo install solana-verify --version "$(cat .solana-verify-version.txt)" --root /mnt/lima-solana/repos/solana-programs/solana-program-workbench/.cargo-root
     Ignored package `solana-verify v0.5.1` is already installed, use --force to override
warning: be sure to add `/mnt/lima-solana/repos/solana-programs/solana-program-workbench/.cargo-root/bin` to your PATH to be able to run the installed binaries
/mnt/lima-solana/repos/solana-programs/solana-program-workbench/.cargo-root/bin/solana-verify build --library-name cow_settlement
Mounting path: /mnt/lima-solana/repos/solana-programs/solana-program-workbench
Workspace path: /mnt/lima-solana/repos/solana-programs/solana-program-workbench
Found docker image for Solana version 4.0.3
Workdir: /build
Building program at /build//programs/settlement/
Building manifest path: /build//programs/settlement/Cargo.toml
No Docker resource limits are set.
You can set the SVB_DOCKER_MEMORY_LIMIT and SVB_DOCKER_CPU_LIMIT environment variables to limit Docker resources.
For example: SVB_DOCKER_MEMORY_LIMIT=2g SVB_DOCKER_CPU_LIMIT=2.
Using container Rust toolchain: 1.93.1-x86_64-unknown-linux-gnu
    Finished `release` profile [optimized] target(s) in 0.73s
Finished building program
Program Solana version: v4.0.3
Docker image Solana version: v4.0.3
f4014794f8341c469130840ab8585be08934a05ba3695929cd7db977d8c1a1fa
Program Id: EzHqcdJssenE2R8xogJ8wpL66PRQet9M6ubpsX4QxpPb

Signature: Lc3HNqM5SVMCTGRjaY75Tipt87LbZkJJnvKziu1qqfHv3n5YCqVgvFkXJSHz32NbtqKMgj6Z52xvA1Ccq3Qdcrm

statePda = ARHLCFhT3UkEdXEvBJDZVRjTiWNe3fCy4nSrfCtg36tZ
  status = already initialized