feat: add rig management package

Types:
- Rig: managed repository with polecats, witness, refinery, mayor
- RigSummary: concise rig overview
- Manager: rig discovery, loading, creation

Manager operations:
- DiscoverRigs: load all registered rigs
- GetRig: get specific rig by name
- RigExists, ListRigNames: query helpers
- AddRig: clone and register new rig
- RemoveRig: unregister rig (keeps files)

Rig structure follows docs/architecture.md:
- polecats/, refinery/rig/, witness/rig/, mayor/rig/

Closes gt-u1j.5

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

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

internal/rig/manager_test.go

@@ -0,0 +1,188 @@
+package rig
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/steveyegge/gastown/internal/config"
+	"github.com/steveyegge/gastown/internal/git"
+)
+
+func setupTestTown(t *testing.T) (string, *config.RigsConfig) {
+	t.Helper()
+	root := t.TempDir()
+
+	rigsConfig := &config.RigsConfig{
+		Version: 1,
+		Rigs:    make(map[string]config.RigEntry),
+	}
+
+	return root, rigsConfig
+}
+
+func createTestRig(t *testing.T, root, name string) {
+	t.Helper()
+
+	rigPath := filepath.Join(root, name)
+	if err := os.MkdirAll(rigPath, 0755); err != nil {
+		t.Fatalf("mkdir rig: %v", err)
+	}
+
+	// Create agent dirs
+	for _, dir := range AgentDirs {
+		dirPath := filepath.Join(rigPath, dir)
+		if err := os.MkdirAll(dirPath, 0755); err != nil {
+			t.Fatalf("mkdir %s: %v", dir, err)
+		}
+	}
+
+	// Create some polecats
+	polecatsDir := filepath.Join(rigPath, "polecats")
+	for _, polecat := range []string{"Toast", "Cheedo"} {
+		if err := os.MkdirAll(filepath.Join(polecatsDir, polecat), 0755); err != nil {
+			t.Fatalf("mkdir polecat: %v", err)
+		}
+	}
+}
+
+func TestDiscoverRigs(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+
+	// Create test rig
+	createTestRig(t, root, "gastown")
+	rigsConfig.Rigs["gastown"] = config.RigEntry{
+		GitURL: "git@github.com:test/gastown.git",
+	}
+
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	rigs, err := manager.DiscoverRigs()
+	if err != nil {
+		t.Fatalf("DiscoverRigs: %v", err)
+	}
+
+	if len(rigs) != 1 {
+		t.Errorf("rigs count = %d, want 1", len(rigs))
+	}
+
+	rig := rigs[0]
+	if rig.Name != "gastown" {
+		t.Errorf("Name = %q, want gastown", rig.Name)
+	}
+	if len(rig.Polecats) != 2 {
+		t.Errorf("Polecats count = %d, want 2", len(rig.Polecats))
+	}
+	if !rig.HasWitness {
+		t.Error("expected HasWitness = true")
+	}
+	if !rig.HasRefinery {
+		t.Error("expected HasRefinery = true")
+	}
+}
+
+func TestGetRig(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+
+	createTestRig(t, root, "test-rig")
+	rigsConfig.Rigs["test-rig"] = config.RigEntry{
+		GitURL: "git@github.com:test/test-rig.git",
+	}
+
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	rig, err := manager.GetRig("test-rig")
+	if err != nil {
+		t.Fatalf("GetRig: %v", err)
+	}
+
+	if rig.Name != "test-rig" {
+		t.Errorf("Name = %q, want test-rig", rig.Name)
+	}
+}
+
+func TestGetRigNotFound(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	_, err := manager.GetRig("nonexistent")
+	if err != ErrRigNotFound {
+		t.Errorf("GetRig = %v, want ErrRigNotFound", err)
+	}
+}
+
+func TestRigExists(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+	rigsConfig.Rigs["exists"] = config.RigEntry{}
+
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	if !manager.RigExists("exists") {
+		t.Error("expected RigExists = true for existing rig")
+	}
+	if manager.RigExists("nonexistent") {
+		t.Error("expected RigExists = false for nonexistent rig")
+	}
+}
+
+func TestRemoveRig(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+	rigsConfig.Rigs["to-remove"] = config.RigEntry{}
+
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	if err := manager.RemoveRig("to-remove"); err != nil {
+		t.Fatalf("RemoveRig: %v", err)
+	}
+
+	if manager.RigExists("to-remove") {
+		t.Error("rig should not exist after removal")
+	}
+}
+
+func TestRemoveRigNotFound(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	err := manager.RemoveRig("nonexistent")
+	if err != ErrRigNotFound {
+		t.Errorf("RemoveRig = %v, want ErrRigNotFound", err)
+	}
+}
+
+func TestListRigNames(t *testing.T) {
+	root, rigsConfig := setupTestTown(t)
+	rigsConfig.Rigs["rig1"] = config.RigEntry{}
+	rigsConfig.Rigs["rig2"] = config.RigEntry{}
+
+	manager := NewManager(root, rigsConfig, git.NewGit(root))
+
+	names := manager.ListRigNames()
+	if len(names) != 2 {
+		t.Errorf("names count = %d, want 2", len(names))
+	}
+}
+
+func TestRigSummary(t *testing.T) {
+	rig := &Rig{
+		Name:        "test",
+		Polecats:    []string{"a", "b", "c"},
+		HasWitness:  true,
+		HasRefinery: false,
+	}
+
+	summary := rig.Summary()
+
+	if summary.Name != "test" {
+		t.Errorf("Name = %q, want test", summary.Name)
+	}
+	if summary.PolecatCount != 3 {
+		t.Errorf("PolecatCount = %d, want 3", summary.PolecatCount)
+	}
+	if !summary.HasWitness {
+		t.Error("expected HasWitness = true")
+	}
+	if summary.HasRefinery {
+		t.Error("expected HasRefinery = false")
+	}
+}