Adopt Go-style module version selection

[itsfuad]

Problem

Current package resolution intentionally supports a narrow stable-semver constraint set for exact versions, comparisons, tilde, caret, latest, and wildcard requests. It resolves constraints during recursive installation but does not implement Go-style Minimal Version Selection or semantic import versioning.

Required design

• Define module identity and major-version import-path rules.
• Replace recursive best-match resolution with deterministic graph-wide MVS.
• Specify upgrade, downgrade, exclusion, and retraction behavior.
• Preserve lockfile determinism and mock registry support.
• Add compatibility and conflict fixtures before migration.
• Remove tactical constraint semantics only after manifest and lockfile migration is defined.

Constraint

Do not extend current compatibility resolver piecemeal. Design canonical graph algorithm and import-version model first.