Improve version handling and asset naming consistency

[tobiase]

Overview

Currently the update system has some fragile version handling patterns that could be improved.

Priority: Low - System works correctly, but could be more maintainable and robust.

Current Issues

1. Asset Name Brittleness: We manually construct expected asset names but GoReleaser generates versioned names like wt_0.4.0_Darwin_all.tar.gz. Our matching logic uses string manipulation workarounds.

2. Binary Name Inconsistency: We support both wt-bin (development name) and worktree-utils (release name) which creates confusion and maintenance overhead.

3. Platform Detection: Manual OS/arch mapping that could leverage existing Go tooling.

4. Version Comparison: Basic string comparison instead of semantic versioning.

Suggested Improvements

1. Standardize Asset Naming

• Use GoReleaser naming patterns consistently
• Or configure GoReleaser to match our expected patterns
• Consider using GitHub API dynamic asset discovery

2. Unify Binary Names

• Choose one canonical name (probably wt-bin for consistency)
• Update GoReleaser config to use consistent binary name
• Remove dual binary name support after transition

3. Use Semantic Versioning Library

• Replace manual version comparison with proper semver
• Handle pre-release versions, build metadata correctly
• Examples: github.com/Masterminds/semver/v3 or golang.org/x/mod/semver

4. Learn from Established Tools

• Study how gh, docker, kubectl handle updates
• Consider using update frameworks like go-github for releases

Current Workarounds

The update system currently works with these workarounds:

• strings.HasSuffix(a.Name, "_"+assetName[3:]+".tar.gz") for versioned assets
• base == "wt-bin" || base == "worktree-utils" for binary names

Benefits of Fixing

• More maintainable update code
• Reduced fragility when changing release processes
• Better error messages for users
• Preparation for more complex update scenarios (checksums, signatures, etc.)