fix(bundler): source macOS bundle version from Cargo

[unohee]

Summary

• resolve the bundled package version through Cargo metadata
• write the numeric major/minor/patch tuple to macOS VST3, CLAP, AU, and standalone plist metadata
• preserve the existing AU-only override and public helper signature
• normalize prerelease/build suffixes because Apple requires numeric plist versions

Verification

• cargo fmt -p nih_plug_xtask -- --check
• cargo test -p nih_plug_xtask (7 passed)
• prerelease/build metadata regression test
• OpenSwarm working-tree review: Decision: APPROVE

Supports de-artifact AUD-829.

[unohee]

🔍 Fresh review of 074dda0 (openswarm pr review --fresh)

✓ Decision: APPROVE
The bundle path resolves the selected workspace package through Cargo metadata and consistently propagates its normalized major.minor.patch version to macOS standalone, VST, CLAP, and AU metadata. Prerelease/build stripping is covered, and the existing public metadata helper retains its prior 1.0.0 behavior.

[unohee]

🔍 Fresh review of 074dda0 (openswarm pr review --fresh)

✓ Decision: APPROVE
The bundle path resolves the selected Cargo package through cargo metadata and consistently propagates its normalized numeric version to macOS standalone, CLAP/VST, and AU metadata. AU-specific overrides remain intact and are validated through the existing integer encoding parser.