Fix GitHub branch detection and complete task execution workflow

- Added dynamic branch detection that falls back to repository default branch
- Fixed sandbox image reference to use local Docker registry
- Completed full task execution pipeline: discovery → claim → sandbox → execution
- Enhanced GitHub client to verify base branch existence and auto-correct
- Successfully tested end-to-end task claiming and execution

🎉 MAJOR MILESTONE: Full Bzzz task execution workflow now functional\!

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

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

github/client.go

@@ -76,6 +76,11 @@ func NewClient(ctx context.Context, config *Config) (*Client, error) {
 		return nil, fmt.Errorf("failed to verify GitHub access: %w", err)
 	}
 	
+	// Verify base branch exists and update if needed
+	if err := client.verifyBaseBranch(); err != nil {
+		return nil, fmt.Errorf("failed to verify base branch: %w", err)
+	}
+	
 	return client, nil
 }
 
@@ -89,6 +94,25 @@ func (c *Client) verifyAccess() error {
 	return nil
 }
 
+// verifyBaseBranch checks if the base branch exists and updates to default if not
+func (c *Client) verifyBaseBranch() error {
+	// Try to get the configured base branch
+	_, _, err := c.client.Git.GetRef(c.ctx, c.config.Owner, c.config.Repository, "heads/"+c.config.BaseBranch)
+	if err != nil {
+		// If the branch doesn't exist, get the repository's default branch
+		repo, _, err := c.client.Repositories.Get(c.ctx, c.config.Owner, c.config.Repository)
+		if err != nil {
+			return fmt.Errorf("failed to get repository info: %w", err)
+		}
+		
+		// Update config to use the default branch
+		if repo.DefaultBranch != nil {
+			c.config.BaseBranch = *repo.DefaultBranch
+		}
+	}
+	return nil
+}
+
 // Task represents a Bzzz task as a GitHub issue
 type Task struct {
 	ID          int64     `json:"id"`

github/hive_integration.go

@@ -12,7 +12,6 @@ import (
 	"github.com/anthonyrawlins/bzzz/pkg/hive"
 	"github.com/anthonyrawlins/bzzz/pkg/types"
 	"github.com/anthonyrawlins/bzzz/pubsub"
-	"github.com/anthonyrawlins/bzzz/reasoning"
 	"github.com/libp2p/go-libp2p/core/peer"
 )
 
@@ -116,6 +115,7 @@ func (hi *HiveIntegration) syncRepositories() {
 				AccessToken: hi.githubToken,
 				Owner:       repo.Owner,
 				Repository:  repo.Repository,
+				BaseBranch:  repo.Branch,
 			}
 			
 			client, err := NewClient(hi.ctx, githubConfig)
@@ -304,7 +304,7 @@ func (hi *HiveIntegration) claimAndExecuteTask(task *types.EnhancedTask) {
 }
 
 // executeTask executes a claimed task with reasoning and coordination
-func (hi *HiveIntegration) executeTask(task *EnhancedTask, repoClient *RepositoryClient) {
+func (hi *HiveIntegration) executeTask(task *types.EnhancedTask, repoClient *RepositoryClient) {
 	// Define the dynamic topic for this task
 	taskTopic := fmt.Sprintf("bzzz/meta/issue/%d", task.Number)
 	hi.pubsub.JoinDynamicTopic(taskTopic)
@@ -344,7 +344,7 @@ func (hi *HiveIntegration) executeTask(task *EnhancedTask, repoClient *Repositor
 }
 
 // requestAssistance publishes a help request to the task-specific topic.
-func (hi *HiveIntegration) requestAssistance(task *EnhancedTask, reason, topic string) {
+func (hi *HiveIntegration) requestAssistance(task *types.EnhancedTask, reason, topic string) {
 	fmt.Printf("🆘 Agent %s is requesting assistance for task #%d: %s\n", hi.config.AgentID, task.Number, reason)
 	hi.hlog.Append(logging.TaskHelpRequested, map[string]interface{}{
 		"task_id": task.Number,