chore: Bump version to 0.9.4

Updated all component versions:
- bd CLI: 0.9.3 → 0.9.4
- Plugin: 0.9.3 → 0.9.4
- MCP server: 0.9.3 → 0.9.4
- Documentation: 0.9.3 → 0.9.4

Generated by scripts/bump-version.sh

cmd/bd/version.go

@@ -8,7 +8,7 @@ import (
 
 const (
 	// Version is the current version of bd
-	Version = "0.9.3"
+	Version = "0.9.4"
 	// Build can be set via ldflags at compile time
 	Build = "dev"
 )