refactor: break down large functions into smaller, focused ones

Major refactoring to improve code maintainability:

1. Split main.go (481 lines → 72 lines) into internal/cli package:
   - flags.go: Command-line flag definitions and parsing
   - handlers.go: General command handlers (version, config, list operations)
   - sync_handlers.go: Sync-specific handlers for all sync operations

2. Refactored sync.go to extract logic into separate files:
   - git_operations.go: Git command helpers (merge, push, fetch, etc.)
   - repository_setup.go: Repository initialization and remote configuration
   - branch_sync.go: Branch synchronization helpers

3. Reduced function sizes to meet 30-line guideline:
   - syncBranch: 104 lines → 26 lines
   - SyncRepository: 97 lines → 44 lines
   - main(): 465 lines → 63 lines
   - getAllBranches: 32 lines → 9 lines

All functionality remains the same, but the code is now more modular,
testable, and easier to understand. Each function has a single, clear
responsibility.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/internal/cli/flags.go b/internal/cli/flags.go
new file mode 100644
index 0000000..c0320c5
--- /dev/null
+++ b/internal/cli/flags.go
@@ -0,0 +1,55 @@
+package cli
+
+import "flag"
+
+// Flags holds all command-line flag values
+type Flags struct {
+	VersionFlag        bool
+	ConfigPath         string
+	ListOrgs           bool
+	ListRepos          bool
+	SyncRepo           string
+	SyncAll            bool
+	SyncCodebergPublic bool
+	SyncGitHubPublic   bool
+	FullSync           bool
+	CreateGitHubRepos  bool
+	CreateCodebergRepos bool
+	DryRun             bool
+	WorkDir            string
+	TestGitHubToken    bool
+}
+
+// ParseFlags parses command-line flags and returns the flags struct
+func ParseFlags() *Flags {
+	f := &Flags{}
+	
+	flag.BoolVar(&f.VersionFlag, "version", false, "print version information")
+	flag.BoolVar(&f.VersionFlag, "v", false, "print version information (short)")
+	flag.StringVar(&f.ConfigPath, "config", "", "path to configuration file")
+	flag.StringVar(&f.ConfigPath, "c", "", "path to configuration file (short)")
+	flag.BoolVar(&f.ListOrgs, "list-orgs", false, "list configured organizations")
+	flag.BoolVar(&f.ListRepos, "list-repos", false, "list configured repositories")
+	flag.StringVar(&f.SyncRepo, "sync", "", "repository name to sync")
+	flag.BoolVar(&f.SyncAll, "sync-all", false, "sync all configured repositories")
+	flag.BoolVar(&f.SyncCodebergPublic, "sync-codeberg-public", false, "sync all public Codeberg repositories to GitHub")
+	flag.BoolVar(&f.SyncGitHubPublic, "sync-github-public", false, "sync all public GitHub repositories to Codeberg")
+	flag.BoolVar(&f.FullSync, "full", false, "full bidirectional sync (enables --sync-codeberg-public --sync-github-public --create-github-repos --create-codeberg-repos)")
+	flag.BoolVar(&f.CreateGitHubRepos, "create-github-repos", false, "automatically create missing GitHub repositories")
+	flag.BoolVar(&f.CreateCodebergRepos, "create-codeberg-repos", false, "automatically create missing Codeberg repositories")
+	flag.BoolVar(&f.DryRun, "dry-run", false, "show what would be synced without actually syncing")
+	flag.StringVar(&f.WorkDir, "work-dir", ".gitsyncer-work", "working directory for cloning repositories")
+	flag.BoolVar(&f.TestGitHubToken, "test-github-token", false, "test GitHub token authentication")
+	
+	flag.Parse()
+	
+	// Handle --full flag by enabling all sync operations
+	if f.FullSync {
+		f.SyncCodebergPublic = true
+		f.SyncGitHubPublic = true
+		f.CreateGitHubRepos = true
+		f.CreateCodebergRepos = true
+	}
+	
+	return f
+}
\ No newline at end of file