Add slug auto-detection, new commands, JSON output, and aliases

[smorin]

Summary

This PR adds several quality-of-life improvements to worktreeflow:

• Slug auto-detection: Commands can now infer the slug from the current working directory when inside a worktree
• New navigation commands: wt-cd, wt-open, and wt-reopen for easier worktree management
• JSON output mode: --json flag for machine-readable output from commands like doctor, wt-list, and wt-status
• Command aliases: Short aliases (e.g., new → wt-new, pub → wt-publish) for faster typing
• Configuration wizard: New init command for interactive setup
• Version command: Display worktreeflow version
• Environment variable support: Global flags can now be set via WTF_* environment variables

Key Changes

Core Manager Enhancements (manager.py)

• Added json_output parameter to GitWorkflowManager.__init__
• Implemented _infer_slug_from_cwd() to detect slug from worktree path pattern {worktree_base}/{repo_name}/{slug}
• Added resolve_slug() method to handle explicit slug or auto-detection with clear error messages
• Added _require_gh() helper to validate GitHub CLI availability with helpful error messages
• Refactored doctor() to support JSON output mode while maintaining rich table display
• Enhanced wt_list() to show last activity dates, staleness indicators, and PR information
• Enhanced wt_status() to support JSON output
• Added three new navigation commands:
  • wt_cd(): Print worktree path for shell composition (cd $(wtf wt-cd slug))
  • wt_open(): Open worktree in editor (auto-detects from $EDITOR or tries code/vim/nano)
  • wt_reopen(): Recreate a worktree from an existing remote branch

CLI Interface (cli.py)

• Implemented AliasGroup custom Click group class to support command aliases
• Added alias mapping: new, pub, pr, up, clean, ls, st, cd, open, reopen
• Added --json global flag for machine-readable output
• Added environment variable support for global flags: WTF_DEBUG, WTF_DRY_RUN, WTF_QUIET, WTF_VERBOSE, WTF_BASE_BRANCH
• Made slug argument optional for commands that support auto-detection: wt-publish, wt-pr, wt-update, wt-clean, wt-status, wt-cd, wt-open
• Added version command to display worktreeflow version
• Added init command for interactive configuration
• Added --open flag to wt-new to open editor after creation
• Updated help text and docstrings to document auto-detection and aliases

Configuration (config.py)

• Added generate_config() function to programmatically generate .worktreeflow.toml content with customizable options

Tests (test_new_features.py)

• Comprehensive test suite for all new features including:
  • Slug auto-detection logic
  • New navigation commands
  • JSON output modes
  • Command aliases
  • Configuration generation
  • GitHub CLI requirement validation

Notable Implementation Details

• Slug auto-detection gracefully falls back to requiring explicit slug with helpful error message
• JSON output is mutually exclusive with --verbose flag
• The wt_open command respects dry-run mode and doesn't spawn editor processes during preview
• PR information in wt_list is only fetched when gh CLI is available and fork/upstream are configured
• All new commands maintain backward compatibility with existing workflows
• Error messages are enhanced with actionable suggestions (e.g., installation links, example commands)

https://claude.ai/code/session_01A1Z3oDtv65NzXVqYaSsn8G