Unify reported snarkOS versions through .cargo/release-version

[Copilot]

Reported versions were coming from multiple crate-local sources (CARGO_PKG_VERSION / PKG_VERSION), which required updating the same release number in several places. This change makes the user-facing/runtime-reported version come from a single root source: .cargo/release-version.

• Centralize the reported version

  • Added shared build-script logic to read .cargo/release-version
  • Normalizes the stored tag (v4.6.0 → 4.6.0)
  • Exposes the result uniformly as SNARKOS_VERSION

• Switch version consumers to the shared source

  • Updated the CLI updater to use SNARKOS_VERSION instead of crate-local CARGO_PKG_VERSION
  • Updated REST and metrics version reporting to stop reading built_info::PKG_VERSION
  • Updated the CDN user agent to use the shared version value

• Align CLI version output

  • snarkos --version now includes the unified release version alongside git branch/commit and enabled features

• Add a focused guardrail

  • Added a unit test in the CLI crate that asserts SNARKOS_VERSION matches .cargo/release-version

.current_version(env!("SNARKOS_VERSION"))

This keeps reported versions tied to one root file without changing the existing package/dependency version structure used by the workspace.