feat(rig): Add --branch flag for custom default branch

Add --branch flag to `gt rig add` to specify a custom default branch
instead of auto-detecting from remote. This supports repositories that
use non-standard default branches like `develop` or `release`.

Changes:
- Add --branch flag to `gt rig add` command
- Store default_branch in rig config.json
- Propagate default branch to refinery, witness, daemon, and all commands
- Rename ensureMainBranch to ensureDefaultBranch for clarity
- Add Rig.DefaultBranch() method for consistent access
- Update crew/manager.go and swarm/manager.go to use rig config

Based on PR #49 by @kustrun - rebased and extended with additional fixes.

Co-authored-by: kustrun <kustrun@users.noreply.github.com>

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/cmd/crew_at.go

@@ -52,8 +52,8 @@ func runCrewAt(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("getting crew worker: %w", err)
 	}
 
-	// Ensure crew workspace is on main branch (persistent roles should not use feature branches)
+	// Ensure crew workspace is on default branch (persistent roles should not use feature branches)
-	ensureMainBranch(worker.ClonePath, fmt.Sprintf("Crew workspace %s/%s", r.Name, name))
+	ensureDefaultBranch(worker.ClonePath, fmt.Sprintf("Crew workspace %s/%s", r.Name, name), r.Path)
 
 	// If --no-tmux, just print the path
 	if crewNoTmux {

internal/cmd/crew_helpers.go

@@ -205,10 +205,11 @@ func attachToTmuxSession(sessionID string) error {
 	return cmd.Run()
 }
 
-// ensureMainBranch checks if a git directory is on main branch.
+// ensureDefaultBranch checks if a git directory is on the default branch.
 // If not, warns the user and offers to switch.
-// Returns true if on main (or switched to main), false if user declined.
+// Returns true if on default branch (or switched to it), false if user declined.
-func ensureMainBranch(dir, roleName string) bool { //nolint:unparam // bool return kept for future callers to check
+// The rigPath parameter is used to look up the configured default branch.
+func ensureDefaultBranch(dir, roleName, rigPath string) bool { //nolint:unparam // bool return kept for future callers to check
 	g := git.NewGit(dir)
 
 	branch, err := g.CurrentBranch()
@@ -217,31 +218,38 @@ func ensureMainBranch(dir, roleName string) bool { //nolint:unparam // bool retu
 		return true
 	}
 
-	if branch == "main" || branch == "master" {
+	// Get configured default branch for this rig
+	defaultBranch := "main" // fallback
+	if rigCfg, err := rig.LoadRigConfig(rigPath); err == nil && rigCfg.DefaultBranch != "" {
+		defaultBranch = rigCfg.DefaultBranch
+	}
+
+	if branch == defaultBranch || branch == "master" {
 		return true
 	}
 
 	// Warn about wrong branch
-	fmt.Printf("\n%s %s is on branch '%s', not main\n",
+	fmt.Printf("\n%s %s is on branch '%s', not %s\n",
 		style.Warning.Render("⚠"),
 		roleName,
-		branch)
+		branch,
-	fmt.Println("  Persistent roles should work on main to avoid orphaned work.")
+		defaultBranch)
+	fmt.Printf("  Persistent roles should work on %s to avoid orphaned work.\n", defaultBranch)
 	fmt.Println()
 
-	// Auto-switch to main
+	// Auto-switch to default branch
-	fmt.Printf("  Switching to main...\n")
+	fmt.Printf("  Switching to %s...\n", defaultBranch)
-	if err := g.Checkout("main"); err != nil {
+	if err := g.Checkout(defaultBranch); err != nil {
-		fmt.Printf("  %s Could not switch to main: %v\n", style.Error.Render("✗"), err)
+		fmt.Printf("  %s Could not switch to %s: %v\n", style.Error.Render("✗"), defaultBranch, err)
-		fmt.Println("  Please manually run: git checkout main && git pull")
+		fmt.Printf("  Please manually run: git checkout %s && git pull\n", defaultBranch)
 		return false
 	}
 
 	// Pull latest
-	if err := g.Pull("origin", "main"); err != nil {
+	if err := g.Pull("origin", defaultBranch); err != nil {
 		fmt.Printf("  %s Pull failed (continuing anyway): %v\n", style.Warning.Render("⚠"), err)
 	} else {
-		fmt.Printf("  %s Switched to main and pulled latest\n", style.Success.Render("✓"))
+		fmt.Printf("  %s Switched to %s and pulled latest\n", style.Success.Render("✓"), defaultBranch)
 	}
 
 	return true

internal/cmd/done.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -10,6 +11,7 @@ import (
 	"github.com/steveyegge/gastown/internal/events"
 	"github.com/steveyegge/gastown/internal/git"
 	"github.com/steveyegge/gastown/internal/mail"
+	"github.com/steveyegge/gastown/internal/rig"
 	"github.com/steveyegge/gastown/internal/style"
 	"github.com/steveyegge/gastown/internal/workspace"
 )
@@ -147,11 +149,17 @@ func runDone(cmd *cobra.Command, args []string) error {
 		agentBeadID = getAgentBeadID(ctx)
 	}
 
-	// For COMPLETED, we need an issue ID and branch must not be main
+	// Get configured default branch for this rig
+	defaultBranch := "main" // fallback
+	if rigCfg, err := rig.LoadRigConfig(filepath.Join(townRoot, rigName)); err == nil && rigCfg.DefaultBranch != "" {
+		defaultBranch = rigCfg.DefaultBranch
+	}
+
+	// For COMPLETED, we need an issue ID and branch must not be the default branch
 	var mrID string
 	if exitType == ExitCompleted {
-		if branch == "main" || branch == "master" {
+		if branch == defaultBranch || branch == "master" {
-			return fmt.Errorf("cannot submit main/master branch to merge queue")
+			return fmt.Errorf("cannot submit %s/master branch to merge queue", defaultBranch)
 		}
 
 		// Check for unpushed commits - branch must be pushed before MR creation
@@ -164,9 +172,6 @@ func runDone(cmd *cobra.Command, args []string) error {
 			return fmt.Errorf("branch has %d unpushed commit(s); run 'git push -u origin %s' first", unpushedCount, branch)
 		}
 
-		// Detect the repo's default branch (main vs master)
-		defaultBranch := g.RemoteDefaultBranch()
-
 		// Check that branch has commits ahead of default branch (prevents submitting stale branches)
 		aheadCount, err := g.CommitsAhead(defaultBranch, branch)
 		if err != nil {

internal/cmd/mq_submit.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"regexp"
 	"strings"
 	"time"
@@ -11,6 +12,7 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/steveyegge/gastown/internal/beads"
 	"github.com/steveyegge/gastown/internal/git"
+	"github.com/steveyegge/gastown/internal/rig"
 	"github.com/steveyegge/gastown/internal/style"
 	"github.com/steveyegge/gastown/internal/workspace"
 )
@@ -78,8 +80,14 @@ func runMqSubmit(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	if branch == "main" || branch == "master" {
+	// Get configured default branch for this rig
-		return fmt.Errorf("cannot submit main/master branch to merge queue")
+	defaultBranch := "main" // fallback
+	if rigCfg, err := rig.LoadRigConfig(filepath.Join(townRoot, rigName)); err == nil && rigCfg.DefaultBranch != "" {
+		defaultBranch = rigCfg.DefaultBranch
+	}
+
+	if branch == defaultBranch || branch == "master" {
+		return fmt.Errorf("cannot submit %s/master branch to merge queue", defaultBranch)
 	}
 
 	// CRITICAL: Verify branch is pushed before creating MR bead
@@ -111,7 +119,7 @@ func runMqSubmit(cmd *cobra.Command, args []string) error {
 	bd := beads.New(cwd)
 
 	// Determine target branch
-	target := "main"
+	target := defaultBranch
 	if mqSubmitEpic != "" {
 		// Explicit --epic flag takes precedence
 		target = "integration/" + mqSubmitEpic
@@ -119,7 +127,7 @@ func runMqSubmit(cmd *cobra.Command, args []string) error {
 		// Auto-detect: check if source issue has a parent epic with an integration branch
 		autoTarget, err := detectIntegrationBranch(bd, g, issueID)
 		if err != nil {
-			// Non-fatal: log and continue with main as target
+			// Non-fatal: log and continue with default branch as target
 			fmt.Printf("  %s\n", style.Dim.Render(fmt.Sprintf("(note: %v)", err)))
 		} else if autoTarget != "" {
 			target = autoTarget

internal/cmd/rig.go

@@ -252,6 +252,7 @@ Examples:
 var (
 	rigAddPrefix       string
 	rigAddLocalRepo    string
+	rigAddBranch       string
 	rigResetHandoff    bool
 	rigResetMail       bool
 	rigResetStale      bool
@@ -281,6 +282,7 @@ func init() {
 
 	rigAddCmd.Flags().StringVar(&rigAddPrefix, "prefix", "", "Beads issue prefix (default: derived from name)")
 	rigAddCmd.Flags().StringVar(&rigAddLocalRepo, "local-repo", "", "Local repo path to share git objects (optional)")
+	rigAddCmd.Flags().StringVar(&rigAddBranch, "branch", "", "Default branch name (default: auto-detected from remote)")
 
 	rigResetCmd.Flags().BoolVar(&rigResetHandoff, "handoff", false, "Clear handoff content")
 	rigResetCmd.Flags().BoolVar(&rigResetMail, "mail", false, "Clear stale mail messages")
@@ -344,6 +346,7 @@ func runRigAdd(cmd *cobra.Command, args []string) error {
 		GitURL:        gitURL,
 		BeadsPrefix:   rigAddPrefix,
 		LocalRepo:     rigAddLocalRepo,
+		DefaultBranch: rigAddBranch,
 	})
 	if err != nil {
 		return fmt.Errorf("adding rig: %w", err)

internal/cmd/start.go

@@ -750,8 +750,8 @@ func runStartCrew(cmd *cobra.Command, args []string) error {
 		fmt.Printf("Crew workspace %s/%s exists\n", rigName, name)
 	}
 
-	// Ensure crew workspace is on main branch
+	// Ensure crew workspace is on default branch
-	ensureMainBranch(worker.ClonePath, fmt.Sprintf("Crew workspace %s/%s", rigName, name))
+	ensureDefaultBranch(worker.ClonePath, fmt.Sprintf("Crew workspace %s/%s", rigName, name), r.Path)
 
 	// Resolve account for Claude config
 	accountsPath := constants.MayorAccountsPath(townRoot)
@@ -933,8 +933,8 @@ func startCrewMember(rigName, crewName, townRoot string) error {
 		return fmt.Errorf("getting crew worker: %w", err)
 	}
 
-	// Ensure crew workspace is on main branch
+	// Ensure crew workspace is on default branch
-	ensureMainBranch(worker.ClonePath, fmt.Sprintf("Crew workspace %s/%s", rigName, crewName))
+	ensureDefaultBranch(worker.ClonePath, fmt.Sprintf("Crew workspace %s/%s", rigName, crewName), r.Path)
 
 	// Create tmux session
 	t := tmux.NewTmux()

internal/crew/manager.go

@@ -85,7 +85,7 @@ func (m *Manager) Add(name string, createBranch bool) (*CrewWorker, error) {
 	}
 
 	crewGit := git.NewGit(crewPath)
-	branchName := "main"
+	branchName := m.rig.DefaultBranch()
 
 	// Optionally create a working branch
 	if createBranch {

internal/daemon/lifecycle.go

@@ -11,6 +11,7 @@ import (
 	"github.com/steveyegge/gastown/internal/beads"
 	"github.com/steveyegge/gastown/internal/config"
 	"github.com/steveyegge/gastown/internal/constants"
+	"github.com/steveyegge/gastown/internal/rig"
 	"github.com/steveyegge/gastown/internal/session"
 	"github.com/steveyegge/gastown/internal/tmux"
 )
@@ -467,6 +468,20 @@ func (d *Daemon) applySessionTheme(sessionName string, parsed *ParsedIdentity) {
 // syncWorkspace syncs a git workspace before starting a new session.
 // This ensures agents with persistent clones (like refinery) start with current code.
 func (d *Daemon) syncWorkspace(workDir string) {
+	// Determine default branch from rig config
+	// workDir is like <townRoot>/<rigName>/<role>/rig or <townRoot>/<rigName>/crew/<name>
+	defaultBranch := "main" // fallback
+	rel, err := filepath.Rel(d.config.TownRoot, workDir)
+	if err == nil {
+		parts := strings.Split(rel, string(filepath.Separator))
+		if len(parts) > 0 {
+			rigPath := filepath.Join(d.config.TownRoot, parts[0])
+			if rigCfg, err := rig.LoadRigConfig(rigPath); err == nil && rigCfg.DefaultBranch != "" {
+				defaultBranch = rigCfg.DefaultBranch
+			}
+		}
+	}
+
 	// Fetch latest from origin
 	fetchCmd := exec.Command("git", "fetch", "origin")
 	fetchCmd.Dir = workDir
@@ -475,7 +490,7 @@ func (d *Daemon) syncWorkspace(workDir string) {
 	}
 
 	// Pull with rebase to incorporate changes
-	pullCmd := exec.Command("git", "pull", "--rebase", "origin", "main")
+	pullCmd := exec.Command("git", "pull", "--rebase", "origin", defaultBranch)
 	pullCmd.Dir = workDir
 	if err := pullCmd.Run(); err != nil {
 		d.logger.Printf("Warning: git pull failed in %s: %v", workDir, err)

internal/refinery/engineer.go

@@ -87,12 +87,16 @@ type Engineer struct {
 
 // NewEngineer creates a new Engineer for the given rig.
 func NewEngineer(r *rig.Rig) *Engineer {
+	cfg := DefaultMergeQueueConfig()
+	// Override target branch with rig's configured default branch
+	cfg.TargetBranch = r.DefaultBranch()
+
 	return &Engineer{
 		rig:         r,
 		beads:       beads.New(r.Path),
 		mrQueue:     mrqueue.New(r.Path),
 		git:         git.NewGit(r.Path),
-		config:      DefaultMergeQueueConfig(),
+		config:      cfg,
 		workDir:     r.Path,
 		output:      os.Stdout,
 		eventLogger: mrqueue.NewEventLoggerFromRig(r.Path),

internal/refinery/manager.go

@@ -359,6 +359,9 @@ func (m *Manager) issueToMR(issue *beads.Issue) *MergeRequest {
 		return nil
 	}
 
+	// Get configured default branch for this rig
+	defaultBranch := m.rig.DefaultBranch()
+
 	fields := beads.ParseMRFields(issue)
 	if fields == nil {
 		// No MR fields in description, construct from title/ID
@@ -367,14 +370,14 @@ func (m *Manager) issueToMR(issue *beads.Issue) *MergeRequest {
 			IssueID:      issue.ID,
 			Status:       MROpen,
 			CreatedAt:    parseTime(issue.CreatedAt),
-			TargetBranch: "main",
+			TargetBranch: defaultBranch,
 		}
 	}
 
-	// Default target to main if not specified
+	// Default target to rig's default branch if not specified
 	target := fields.Target
 	if target == "" {
-		target = "main"
+		target = defaultBranch
 	}
 
 	return &MergeRequest{

internal/rig/manager.go

@@ -160,6 +160,7 @@ type AddRigOptions struct {
 	GitURL        string // Repository URL
 	BeadsPrefix   string // Beads issue prefix (defaults to derived from name)
 	LocalRepo     string // Optional local repo for reference clones
+	DefaultBranch string // Default branch (defaults to auto-detected from remote)
 }
 
 func resolveLocalRepo(path, gitURL string) (string, string) {
@@ -285,8 +286,17 @@ func (m *Manager) AddRig(opts AddRigOptions) (*Rig, error) {
 	fmt.Printf("   ✓ Created shared bare repo\n")
 	bareGit := git.NewGitWithDir(bareRepoPath, "")
 
-	// Detect default branch (main, master, etc.)
+	// Determine default branch: use provided value or auto-detect from remote
-	defaultBranch := bareGit.DefaultBranch()
+	var defaultBranch string
+	if opts.DefaultBranch != "" {
+		defaultBranch = opts.DefaultBranch
+	} else {
+		// Try to get default branch from remote first, fall back to local detection
+		defaultBranch = bareGit.RemoteDefaultBranch()
+		if defaultBranch == "" {
+			defaultBranch = bareGit.DefaultBranch()
+		}
+	}
 	rigConfig.DefaultBranch = defaultBranch
 	// Re-save config with default branch
 	if err := m.saveRigConfig(rigPath, rigConfig); err != nil {
@@ -314,6 +324,12 @@ func (m *Manager) AddRig(opts AddRigOptions) (*Rig, error) {
 			return nil, fmt.Errorf("cloning for mayor: %w", err)
 		}
 	}
+
+	// Checkout the default branch for mayor (clone defaults to remote's HEAD, not our configured branch)
+	mayorGit := git.NewGitWithDir("", mayorRigPath)
+	if err := mayorGit.Checkout(defaultBranch); err != nil {
+		return nil, fmt.Errorf("checking out default branch for mayor: %w", err)
+	}
 	fmt.Printf("   ✓ Created mayor clone\n")
 
 	// Check if source repo has .beads/ with its own prefix - if so, use that prefix.

internal/rig/types.go

@@ -79,3 +79,13 @@ func (r *Rig) BeadsPath() string {
 	}
 	return r.Path
 }
+
+// DefaultBranch returns the configured default branch for this rig.
+// Falls back to "main" if not configured or if config cannot be loaded.
+func (r *Rig) DefaultBranch() string {
+	cfg, err := LoadRigConfig(r.Path)
+	if err != nil || cfg.DefaultBranch == "" {
+		return "main"
+	}
+	return cfg.DefaultBranch
+}

internal/swarm/manager.go

@@ -88,7 +88,7 @@ func (m *Manager) LoadSwarm(epicID string) (*Swarm, error) {
 		EpicID:       epicID,
 		BaseCommit:   baseCommit,
 		Integration:  fmt.Sprintf("swarm/%s", epicID),
-		TargetBranch: "main",
+		TargetBranch: m.rig.DefaultBranch(),
 		State:        state,
 		Workers:      []string{}, // Discovered from active tasks
 		Tasks:        []SwarmTask{},

internal/witness/handlers.go

@@ -12,6 +12,7 @@ import (
 	"github.com/steveyegge/gastown/internal/beads"
 	"github.com/steveyegge/gastown/internal/git"
 	"github.com/steveyegge/gastown/internal/mail"
+	"github.com/steveyegge/gastown/internal/rig"
 	"github.com/steveyegge/gastown/internal/tmux"
 	"github.com/steveyegge/gastown/internal/workspace"
 )
@@ -746,12 +747,12 @@ func AutoNukeIfClean(workDir, rigName, polecatName string) *NukePolecatResult {
 	return result
 }
 
-// verifyCommitOnMain checks if the polecat's current commit is on main.
+// verifyCommitOnMain checks if the polecat's current commit is on the default branch.
 // This prevents nuking a polecat whose work wasn't actually merged.
 //
 // Returns:
-//   - true, nil: commit is verified on main
+//   - true, nil: commit is verified on default branch
-//   - false, nil: commit is NOT on main (don't nuke!)
+//   - false, nil: commit is NOT on default branch (don't nuke!)
 //   - false, error: couldn't verify (treat as unsafe)
 func verifyCommitOnMain(workDir, rigName, polecatName string) (bool, error) {
 	// Find town root from workDir
@@ -760,6 +761,12 @@ func verifyCommitOnMain(workDir, rigName, polecatName string) (bool, error) {
 		return false, fmt.Errorf("finding town root: %v", err)
 	}
 
+	// Get configured default branch for this rig
+	defaultBranch := "main" // fallback
+	if rigCfg, err := rig.LoadRigConfig(filepath.Join(townRoot, rigName)); err == nil && rigCfg.DefaultBranch != "" {
+		defaultBranch = rigCfg.DefaultBranch
+	}
+
 	// Construct polecat path: <townRoot>/<rigName>/polecats/<polecatName>
 	polecatPath := filepath.Join(townRoot, rigName, "polecats", polecatName)
 
@@ -772,16 +779,16 @@ func verifyCommitOnMain(workDir, rigName, polecatName string) (bool, error) {
 		return false, fmt.Errorf("getting polecat HEAD: %w", err)
 	}
 
-	// Verify it's an ancestor of main (i.e., it's been merged)
+	// Verify it's an ancestor of default branch (i.e., it's been merged)
-	// We use the polecat's git context to check main
+	// We use the polecat's git context to check
-	isOnMain, err := g.IsAncestor(commitSHA, "origin/main")
+	isOnDefaultBranch, err := g.IsAncestor(commitSHA, "origin/"+defaultBranch)
 	if err != nil {
 		// Try without origin/ prefix in case remote isn't set up
-		isOnMain, err = g.IsAncestor(commitSHA, "main")
+		isOnDefaultBranch, err = g.IsAncestor(commitSHA, defaultBranch)
 		if err != nil {
-			return false, fmt.Errorf("checking if commit is on main: %w", err)
+			return false, fmt.Errorf("checking if commit is on %s: %w", defaultBranch, err)
 		}
 	}
 
-	return isOnMain, nil
+	return isOnDefaultBranch, nil
 }