Evaluate SwiftGitX hybrid adoption: in-process reads, Process for worktrees

[davidpoblador]

Context

See docs/swiftgitx-feasibility.md for full analysis.

Proposal

Use SwiftGitX for frequent read-only git operations (repoInfo, status, branch detection) while keeping Process("git") for worktree management. This gives in-process performance and type-safe errors without needing worktree support from the library.

Benefits

• repoInfo() runs every 15s per project - no fork+exec overhead
• hasUncommittedChanges() instant instead of spawning process
• Type-safe errors instead of parsing stderr
• No PATH resolution needed for read operations

Trigger conditions

• SwiftGitX reaches 1.0 with stable API
• We need richer git integration (blame, diff, file watching)
• Performance profiling shows git Process calls are a bottleneck

Effort

~500 lines of adapter code, 2-3 days. See docs/swiftgitx-feasibility.md for details.