Merge hanzo/mpc additions: ConsensusKV, HSM providers, policy engine, rename CLI to mpc-cli

- pkg/infra: Add abstract KV interface, ConsensusKV (dual-cert BFT with
  Ed25519 + ML-DSA-65), NatsKV, ConsulKVAdapter, HybridKV, SQLiteMeta
  with full test coverage
- pkg/hsm: Add Provider interface and implementations for AWS KMS,
  GCP Cloud KMS, Azure Key Vault, Zymbit HSM, Hanzo KMS, and file-based
  providers with registry and tests. Rename existing FileProvider to
  FilePasswordProvider to avoid collision with new Provider interface
- pkg/policy: Add transaction governance engine with signers, roles,
  spending limits, whitelist/blacklist, time windows, rate limiting,
  approval workflow, audit log, and FHE private policy evaluation
- contracts: Add ThresholdPolicy.sol for on-chain policy enforcement
- cmd: Rename lux-mpc-cli to mpc-cli
- Makefile: Update build targets for mpc-cli

cmd/mpc-cli/main.go

@@ -16,8 +16,8 @@ const (
 
 func main() {
 	cmd := &cli.Command{
-		Name:  "lux-mpc-cli",
-		Usage: "Lux MPC node management tools",
+		Name:  "mpc-cli",
+		Usage: "MPC node management tools",
 		Commands: []*cli.Command{
 			{
 				Name:   "generate-peers",
@@ -154,7 +154,7 @@ func main() {
 				Name:  "version",
 				Usage: "Display detailed version information",
 				Action: func(ctx context.Context, c *cli.Command) error {
-					fmt.Printf("lux-mpc-cli version %s\n", VERSION)
+					fmt.Printf("mpc-cli version %s\n", VERSION)
 					return nil
 				},
 			},