feat(agent): add Chocolatey package broker support

[Vladyslav Nikonov (vnikonov-devolutions)]

Adds Chocolatey as a Windows package broker manager so the Devolutions Agent can build and execute install, update, and uninstall operations through choco.exe.

This is a draft because it depends on the shared protocol package publishing ManagerName::Chocolatey. Local validation was performed with temporary [patch.crates-io] entries pointing at D:\now-proto\policies\rust\...; those local absolute-path patches are intentionally not included in this PR.

Issue: TBD

[Vladyslav Nikonov (vnikonov-devolutions)]

Implementation notes:

• Adds a dedicated Chocolatey command builder for install, upgrade, and uninstall operations.
• Mirrors UniGetUI Chocolatey semantics where applicable: install, upgrade, uninstall, -y, --no-progress, --source, --notsilent, --forcex86, --prerelease, --ignore-checksums --force, and version pinning with --allow-downgrade.
• Rejects unsupported or security-sensitive options explicitly instead of silently ignoring them: package channels, user scope, ARM64/neutral architecture, architecture on uninstall, custom install locations, arbitrary custom parameters, no-upgrade, uninstall-previous, and install-only flags on uninstall.
• Extends Windows executor preparation so Chocolatey commands run through the protected temporary batch wrapper and resolve cmd.exe from System32.
• Resolves Chocolatey through ChocolateyInstall, defaulting to %ProgramData%\chocolatey, and currently accepts only the trusted system Chocolatey folder path; broader SID/ACL-based trust checks are intentionally left for follow-up.
• Adds focused unit coverage for Chocolatey command construction, rejection behavior, capabilities, and executor script preparation.

Testing:

• cargo test -p devolutions-agent chocolatey -- --nocapture
• cargo test -p devolutions-agent broker::command_builder -- --nocapture
• cargo clippy -p devolutions-agent --tests -- -D warnings

Protocol dependency:

• This draft depends on the shared now-policy-api crate publishing ManagerName::Chocolatey.
• Local validation used temporary root [patch.crates-io] entries pointing to D:\now-proto\policies\rust\...; those local patches are not committed to this PR.