Show actor on status/pinned change events in activity feed

Added actor field to RPC client and set it before daemon requests.
This ensures status changes (like pinned events) show who performed
the action in bd activity output.

Changes:
- Added actor field to Client struct
- Added SetActor method to set actor for audit trail
- Modified ExecuteWithCwd to include actor in RPC requests
- Updated main.go to call SetActor after daemon connection

Fixes gt-1ydd9

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

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

cmd/bd/main.go

@@ -522,6 +522,7 @@ var rootCmd = &cobra.Command{
 								}
 								health, healthErr = client.Health()
 								if healthErr == nil && health.Status == statusHealthy {
+									client.SetActor(actor)
 									daemonClient = client
 									daemonStatus.Mode = cmdDaemon
 									daemonStatus.Connected = true
@@ -539,6 +540,7 @@ var rootCmd = &cobra.Command{
 							health.Version, Version)
 					} else {
 						// Daemon is healthy and compatible - use it
+						client.SetActor(actor)
 						daemonClient = client
 						daemonStatus.Mode = cmdDaemon
 						daemonStatus.Connected = true
@@ -589,6 +591,7 @@ var rootCmd = &cobra.Command{
 						// Check health of auto-started daemon
 						health, healthErr := client.Health()
 						if healthErr == nil && health.Status == statusHealthy {
+							client.SetActor(actor)
 							daemonClient = client
 							daemonStatus.Mode = cmdDaemon
 							daemonStatus.Connected = true