refactor(gitops): update fetch / checkout paths and hook command wiring for v2 + trail

- Comment and ref name updates for trace/checkpoints/v1 and refs/trace/
- Minor hook command adjustments to support the new trail/review event watching
- Prep work for the broader trail feature on this branch

Author: Patel230

cmd/trace/cli/git_operations.go

@@ -128,7 +128,7 @@ func IsOnDefaultBranch(ctx context.Context) (bool, string, error) {
 	// If we couldn't determine from remote, use common defaults
 	if defaultBranch == "" {
 		// Check if current branch is a common default name
-		if currentBranch == "main" || currentBranch == "master" {
+		if currentBranch == defaultBaseBranch || currentBranch == masterBaseBranch {
 			return true, currentBranch, nil
 		}
 		return false, currentBranch, nil
@@ -151,11 +151,11 @@ func getDefaultBranchFromRemote(repo *git.Repository) string {
 	}
 
 	// Fallback: check if origin/main or origin/master exists
-	if _, err := repo.Reference(plumbing.NewRemoteReferenceName("origin", "main"), true); err == nil {
-		return "main"
+	if _, err := repo.Reference(plumbing.NewRemoteReferenceName("origin", defaultBaseBranch), true); err == nil {
+		return defaultBaseBranch
 	}
-	if _, err := repo.Reference(plumbing.NewRemoteReferenceName("origin", "master"), true); err == nil {
-		return "master"
+	if _, err := repo.Reference(plumbing.NewRemoteReferenceName("origin", masterBaseBranch), true); err == nil {
+		return masterBaseBranch
 	}
 
 	return ""

cmd/trace/cli/hooks_cmd.go

@@ -16,6 +16,7 @@ import (
 	_ "github.com/GrayCodeAI/trace/cmd/trace/cli/agent/factoryaidroid"
 	_ "github.com/GrayCodeAI/trace/cmd/trace/cli/agent/geminicli"
 	_ "github.com/GrayCodeAI/trace/cmd/trace/cli/agent/opencode"
+	_ "github.com/GrayCodeAI/trace/cmd/trace/cli/agent/pi"
 	_ "github.com/GrayCodeAI/trace/cmd/trace/cli/agent/vogon"
 
 	// support external agents