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>

internal/rpc/client.go

@@ -37,6 +37,7 @@ type Client struct {
 	socketPath string
 	timeout    time.Duration
 	dbPath     string // Expected database path for validation
+	actor      string // Actor for audit trail (who is performing operations)
 }
 
 // TryConnect attempts to connect to the daemon socket
@@ -157,6 +158,11 @@ func (c *Client) SetDatabasePath(dbPath string) {
 	c.dbPath = dbPath
 }
 
+// SetActor sets the actor for audit trail (who is performing operations)
+func (c *Client) SetActor(actor string) {
+	c.actor = actor
+}
+
 // Execute sends an RPC request and waits for a response
 func (c *Client) Execute(operation string, args interface{}) (*Response, error) {
 	return c.ExecuteWithCwd(operation, args, "")
@@ -177,6 +183,7 @@ func (c *Client) ExecuteWithCwd(operation string, args interface{}, cwd string)
 	req := Request{
 		Operation:     operation,
 		Args:          argsJSON,
+		Actor:         c.actor, // Who is performing this operation
 		ClientVersion: ClientVersion,
 		Cwd:           cwd,
 		ExpectedDB:    c.dbPath, // Send expected database path for validation