Scaffold dd0c/drift Go agent: CLI, scanner, scrubber, reporter, models

- cobra CLI: check (one-shot), watch (SQS consumer), version
- models: DriftReport, DriftedResource, severity classification (critical/high/medium/low)
- scanner: Terraform v4 state parser, resource counter
- scrubber: regex + Shannon entropy secret detection (strict/permissive/off modes)
- reporter: mTLS HTTP client with nonce replay prevention
- tests: severity classification (8 cases), scrubber (AWS keys, RSA, entropy, attributes)

products/02-iac-drift-detection/agent/go.mod

@@ -0,0 +1,12 @@
+module github.com/dd0c/drift-agent
+
+go 1.22
+
+require (
+	github.com/hashicorp/hcl/v2 v2.20.0
+	github.com/hashicorp/terraform-json v0.21.0
+	github.com/spf13/cobra v1.8.0
+	go.uber.org/zap v1.27.0
+	golang.org/x/crypto v0.22.0
+	google.golang.org/protobuf v1.33.0
+)