feat(install): add partial version number support

[CalvinAllen]

Summary

• Add partial version resolution to the install command
• Users can now specify major-only or major.minor versions

Examples

• dtvem install node 22 resolves to latest 22.x.x (e.g., 22.15.0)
• dtvem install python 3.12 resolves to latest 3.12.x (e.g., 3.12.1)
• dtvem install node 22.0.0 still works as exact version

Changes

• New src/internal/version/ package with version matching logic
• Updated src/cmd/install.go to resolve partial versions before installation
• Added comprehensive unit tests
• Added e2e integration tests for all runtimes

Test plan

• Unit tests pass (go test ./src/...)
• Linting passes (npm run check)
• E2E tests pass (requires feat(dtvem): add partial version resolution integration tests .github#36 to be merged first)

Closes #188

[CalvinAllen]

/release-note dtvem now has support for installing runtimes using partial version match! dtvem install node 24 - latest minor and revision for the 24 line. dtvem install ruby 3.1 - latest revision for the 3.1 line. Try it out today!