Add build info resolution and version display in help overlay

[someson]

Summary

This PR enhances version information handling by automatically resolving build metadata from Go's build info when release ldflags are not set, and displays the version in the help overlay for better visibility during bug reports.

Key Changes

• New buildinfo.go module: Implements fillBuildInfo() and resolveBuildInfo() functions that intelligently extract version, commit hash, and build date from Go's runtime build info

  • Handles multiple build scenarios: Goreleaser releases, go install @vX.Y.Z, and local go build in git checkouts
  • Distinguishes between tagged versions and pseudo-versions/development builds
  • Detects dirty working trees and appends -dirty suffix to commit hashes
  • Truncates commit hashes to 7 characters for readability

• Version string formatting: Extracted version display logic into versionString() function with consistent format: "azform X.Y.Z (commit, date)"

• Help overlay enhancement: Displays version information right-aligned on the help title line, making it immediately visible when users open the help overlay (the natural place to look for version info when filing bug reports)

• Integration:

  • fillBuildInfo() called early in main() to populate global version variables
  • Version string now shown in usage/help output
  • Updated tests to verify version display in help overlay

Implementation Details

• Uses regex pattern matching to distinguish pseudo-versions from tagged versions
• Respects ldflags precedence: if version/commit/date are already set by build tools, they are not overwritten
• Keeps "dev" version for local builds to avoid cache invalidation on every commit while still providing commit hash for identification
• Gracefully handles missing or incomplete build metadata

https://claude.ai/code/session_012a4ih1YQN5a7BsPynuErjY