feat: git status tracking (#6)

Fixes #4

## Purpose

Adds support to see git information in the hive status

Author: hay-kot

internal/core/config/config.go

@@ -32,12 +32,18 @@ var defaultKeybindings = map[string]Keybinding{
 // Config holds the application configuration.
 type Config struct {
 	Commands    Commands              `yaml:"commands"`
+	Git         GitConfig             `yaml:"git"`
 	GitPath     string                `yaml:"git_path"`
 	Keybindings map[string]Keybinding `yaml:"keybindings"`
 	Hooks       []Hook                `yaml:"hooks"`
 	DataDir     string                `yaml:"-"` // set by caller, not from config file
 }
 
+// GitConfig holds git-related configuration.
+type GitConfig struct {
+	StatusWorkers int `yaml:"status_workers"`
+}
+
 // Hook defines setup commands for specific repositories.
 type Hook struct {
 	// Pattern matches against remote URL (supports glob patterns).
@@ -67,6 +73,9 @@ func DefaultConfig() Config {
 			Spawn:   []string{},
 			Recycle: []string{"git reset --hard", "git checkout main", "git pull"},
 		},
+		Git: GitConfig{
+			StatusWorkers: 3,
+		},
 		GitPath:     "git",
 		Keybindings: map[string]Keybinding{},
 	}
@@ -97,13 +106,24 @@ func Load(configPath, dataDir string) (*Config, error) {
 	// Merge user keybindings into defaults (user config overrides defaults)
 	cfg.Keybindings = mergeKeybindings(defaultKeybindings, cfg.Keybindings)
 
+	// Apply defaults for zero values
+	cfg.applyDefaults()
+
 	if err := cfg.Validate(); err != nil {
 		return nil, fmt.Errorf("invalid config: %w", err)
 	}
 
 	return &cfg, nil
 }
 
+// applyDefaults sets default values for any unset configuration options.
+func (c *Config) applyDefaults() {
+	defaults := DefaultConfig()
+	if c.Git.StatusWorkers == 0 {
+		c.Git.StatusWorkers = defaults.Git.StatusWorkers
+	}
+}
+
 // mergeKeybindings merges user keybindings into defaults.
 // User keybindings override defaults for the same key.
 func mergeKeybindings(defaults, user map[string]Keybinding) map[string]Keybinding {
@@ -132,6 +152,10 @@ func (c *Config) Validate() error {
 		return fmt.Errorf("data directory cannot be empty")
 	}
 
+	if c.Git.StatusWorkers < 1 {
+		return fmt.Errorf("git.status_workers must be at least 1")
+	}
+
 	for key, kb := range c.Keybindings {
 		if kb.Action == "" && kb.Sh == "" {
 			return fmt.Errorf("keybinding %q must have either action or sh", key)

internal/core/git/executor.go

@@ -62,3 +62,108 @@ func (e *Executor) IsClean(ctx context.Context, dir string) (bool, error) {
 	}
 	return len(strings.TrimSpace(string(out))) == 0, nil
 }
+
+func (e *Executor) Branch(ctx context.Context, dir string) (string, error) {
+	// Try to get branch name first
+	out, err := e.exec.RunDir(ctx, dir, e.gitPath, "branch", "--show-current")
+	if err != nil {
+		return "", fmt.Errorf("git branch: %w", err)
+	}
+
+	branch := strings.TrimSpace(string(out))
+	if branch != "" {
+		return branch, nil
+	}
+
+	// Empty branch name means detached HEAD - get short commit SHA
+	out, err = e.exec.RunDir(ctx, dir, e.gitPath, "rev-parse", "--short", "HEAD")
+	if err != nil {
+		return "", fmt.Errorf("git rev-parse: %w", err)
+	}
+
+	return strings.TrimSpace(string(out)), nil
+}
+
+func (e *Executor) DefaultBranch(ctx context.Context, dir string) (string, error) {
+	// Get the default branch from origin's HEAD reference
+	out, err := e.exec.RunDir(ctx, dir, e.gitPath, "symbolic-ref", "refs/remotes/origin/HEAD", "--short")
+	if err != nil {
+		return "", fmt.Errorf("git symbolic-ref: %w", err)
+	}
+
+	// Output is "origin/main" or "origin/master", strip the "origin/" prefix
+	branch := strings.TrimSpace(string(out))
+	branch = strings.TrimPrefix(branch, "origin/")
+
+	return branch, nil
+}
+
+func (e *Executor) DiffStats(ctx context.Context, dir string) (additions, deletions int, err error) {
+	// Get the default branch to compare against
+	defaultBranch, err := e.DefaultBranch(ctx, dir)
+	if err != nil {
+		// Fallback to comparing against HEAD if we can't determine default branch
+		defaultBranch = "HEAD"
+	}
+
+	var out []byte
+	if defaultBranch == "HEAD" {
+		// Compare working directory against HEAD
+		out, err = e.exec.RunDir(ctx, dir, e.gitPath, "diff", "--shortstat", "HEAD")
+	} else {
+		// Compare current branch against default branch (e.g., main...HEAD)
+		out, err = e.exec.RunDir(ctx, dir, e.gitPath, "diff", "--shortstat", defaultBranch+"...HEAD")
+	}
+
+	if err != nil {
+		return 0, 0, fmt.Errorf("git diff: %w", err)
+	}
+
+	return parseDiffStats(string(out))
+}
+
+// parseDiffStats parses git diff --shortstat output.
+// Example: " 3 files changed, 10 insertions(+), 5 deletions(-)"
+func parseDiffStats(output string) (additions, deletions int, err error) {
+	output = strings.TrimSpace(output)
+	if output == "" {
+		return 0, 0, nil
+	}
+
+	// Parse insertions
+	if idx := strings.Index(output, "insertion"); idx != -1 {
+		// Find the number before "insertion"
+		start := strings.LastIndex(output[:idx], ",")
+		if start == -1 {
+			start = strings.LastIndex(output[:idx], "changed")
+		}
+		if start != -1 {
+			numStr := strings.TrimSpace(output[start+1 : idx])
+			numStr = strings.Fields(numStr)[0]
+			additions, _ = parseInt(numStr)
+		}
+	}
+
+	// Parse deletions
+	if idx := strings.Index(output, "deletion"); idx != -1 {
+		// Find the number before "deletion"
+		start := strings.LastIndex(output[:idx], ",")
+		if start != -1 {
+			numStr := strings.TrimSpace(output[start+1 : idx])
+			numStr = strings.Fields(numStr)[0]
+			deletions, _ = parseInt(numStr)
+		}
+	}
+
+	return additions, deletions, nil
+}
+
+func parseInt(s string) (int, error) {
+	var n int
+	for _, c := range s {
+		if c >= '0' && c <= '9' {
+			n = n*10 + int(c-'0')
+		}
+	}
+	return n, nil
+}