feat(gcp-to-aws): post-Estimate what-if workshop checkpoint

migrate/plugins/migration-to-aws/fixtures/README.md

@@ -3,6 +3,7 @@
 Also see:
 
 - `heroku-workshop/` — Heroku what-if workshop seed + arm64 reprice snapshot + `check_expected_workshop.py`
+- `gcp-workshop/` — GCP what-if workshop seed + graviton reprice + `check_expected_workshop.py`
 - `vercel-workshop/` — Vercel what-if workshop seed + outcome-B/x86 reprice + `check_expected_workshop.py`
 
 ## Migration report reference fixture

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/README.md

@@ -0,0 +1,28 @@
+# GCP what-if workshop fixtures
+
+Infra-route pilot for `gcp-to-aws` (`references/phases/workshop/`).
+
+| Path                         | Role                                                                                      |
+| ---------------------------- | ----------------------------------------------------------------------------------------- |
+| `seed/`                      | Post-Estimate baseline (`cpu_architecture=x86`, real Q11b prompt, mixed graviton_profile) |
+| `after-graviton-reprice/`    | After Apply with `graviton` + caveat (worker stays x86)                                   |
+| `check_expected_workshop.py` | Stdlib asserter                                                                           |
+
+```bash
+python3 check_expected_workshop.py after-graviton-reprice
+```
+
+## House replay bar
+
+Before merge: from `seed/`, enter workshop → set CPU architecture to `graviton`
+(sheet must show the incompatible-worker caveat) → Apply & reprice → Compare →
+asserter PASS. The committed `after-graviton-reprice/` was produced by that
+mechanical path (inventory bytes frozen; worker remains `X86_64`;
+`workshop.graviton_note` set). Prefer also a fresh-agent transcript on the PR.
+
+## Merge coordination
+
+Land **#149** (GCP live discovery) before or rebase this branch onto it — both
+touch `discover.md`. Workshop PRs (#152 Heroku, #153 Vercel, #154 GCP) all edit
+`fixtures/README.md`; expect small registry conflicts — last merger wins by
+keeping all three bullets.

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/.phase-status.json

@@ -0,0 +1,14 @@
+{
+  "migration_id": "0719-gcp-ws",
+  "last_updated": "2026-07-19T19:05:00Z",
+  "current_phase": "estimate",
+  "phases": {
+    "discover": "completed",
+    "clarify": "completed",
+    "design": "completed",
+    "estimate": "completed",
+    "workshop": "in_progress",
+    "generate": "pending",
+    "feedback": "pending"
+  }
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/aws-design.json

@@ -0,0 +1,40 @@
+{
+  "phase": "design",
+  "services": [
+    {
+      "aws_service": "ECS Fargate",
+      "source_resource_id": "run:web",
+      "aws_config": {
+        "cpu_architecture": "ARM64",
+        "region": "us-east-1"
+      },
+      "graviton": {
+        "compatibility": "ready",
+        "target_architecture": "arm64",
+        "selected": true
+      }
+    },
+    {
+      "aws_service": "ECS Fargate",
+      "source_resource_id": "run:worker",
+      "aws_config": {
+        "cpu_architecture": "X86_64",
+        "region": "us-east-1"
+      },
+      "graviton": {
+        "compatibility": "incompatible",
+        "target_architecture": "x86_64",
+        "selected": false
+      }
+    },
+    {
+      "aws_service": "RDS PostgreSQL",
+      "source_resource_id": "sql:main",
+      "aws_config": {
+        "instance_class": "db.t4g.micro",
+        "multi_az": false,
+        "region": "us-east-1"
+      }
+    }
+  ]
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/estimation-infra.json

@@ -0,0 +1,29 @@
+{
+  "phase": "estimate",
+  "pricing_source": {
+    "status": "cached"
+  },
+  "projected_costs": {
+    "aws_monthly_premium": 110.0,
+    "aws_monthly_balanced": 85.0,
+    "aws_monthly_optimized": 62.0
+  },
+  "complexity_tier": "small",
+  "recommendation": {
+    "path": "migrate_optimized",
+    "path_label": "Migrate optimized",
+    "migrate_if": [
+      "costs favor AWS"
+    ],
+    "stay_if": [
+      "heavy custom networking"
+    ]
+  },
+  "architecture_comparison": {
+    "graviton_monthly": 85.0,
+    "x86_equivalent_monthly": 95.0,
+    "savings_amount": 10.0,
+    "savings_percent": 10.5,
+    "note": "Partial Graviton: worker remains x86 (incompatible). Hourly savings only on ready services."
+  }
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/gcp-resource-inventory.json

@@ -0,0 +1,46 @@
+{
+  "migration_id": "0719-gcp-ws",
+  "resources": [
+    {
+      "id": "run:web",
+      "type": "google_cloud_run_v2_service",
+      "name": "web"
+    },
+    {
+      "id": "run:worker",
+      "type": "google_cloud_run_v2_service",
+      "name": "worker"
+    },
+    {
+      "id": "sql:main",
+      "type": "google_sql_database_instance",
+      "name": "main"
+    }
+  ],
+  "graviton_profile": [
+    {
+      "service_name": "web",
+      "tier": "ready",
+      "target_architecture": "arm64",
+      "signals": [
+        "python-3.11",
+        "no-native-extensions"
+      ],
+      "caveats": [],
+      "source": "app_code"
+    },
+    {
+      "service_name": "worker",
+      "tier": "incompatible",
+      "target_architecture": "x86_64",
+      "signals": [
+        "platform: linux/amd64",
+        "native-c-extension"
+      ],
+      "caveats": [
+        "Pinned linux/amd64 image; native extension lacks arm64 wheel"
+      ],
+      "source": "app_code"
+    }
+  ]
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/preferences.json

@@ -0,0 +1,38 @@
+{
+  "design_constraints": {
+    "target_region": {
+      "value": "us-east-1",
+      "chosen_by": "default",
+      "question_id": "Q1",
+      "prompt": "Where are your users located?",
+      "design_consequence": "All resources deploy in us-east-1; Bedrock model availability checked for this region"
+    },
+    "availability": {
+      "value": "single-az",
+      "chosen_by": "default",
+      "question_id": "Q6",
+      "prompt": "What level of uptime does your application require?",
+      "design_consequence": "single-az drives RDS single-AZ vs Multi-AZ vs Aurora selection"
+    },
+    "kubernetes": {
+      "value": "ecs-fargate",
+      "chosen_by": "user",
+      "question_id": "Q8",
+      "prompt": "How do you feel about Kubernetes?",
+      "design_consequence": "ecs-fargate selects EKS vs ECS Fargate vs mixed posture"
+    },
+    "cpu_architecture": {
+      "value": "graviton",
+      "chosen_by": "user",
+      "question_id": "Q11b",
+      "prompt": "Some of your services have ARM64 compatibility considerations. Graviton (ARM64) instances are ~15\u201320% cheaper per hour. Your Python workloads appear compatible; worker has a linux/amd64 pin and native C extension. How would you like to proceed?",
+      "design_consequence": "Graviton for ready + conditional services; x86 only for incompatible ones (worker stays x86)"
+    }
+  },
+  "workshop": {
+    "active": true,
+    "last_sheet_at": "2026-07-19T19:05:00Z",
+    "active_scenario_id": "scenario-002",
+    "graviton_note": "1 incompatible \u2014 graviton applies where tier: ready; incompatible entries stay x86"
+  }
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/scenarios/index.json

@@ -0,0 +1,22 @@
+{
+  "baseline_scenario_id": "scenario-001",
+  "active_scenario_id": "scenario-002",
+  "max_scenarios": 5,
+  "inventory_fingerprint": "816eb4c04f8d719c01705a86f250f1292937fa13533db7d38173d4182adf84ee",
+  "scenarios": [
+    {
+      "scenario_id": "scenario-001",
+      "label": "baseline",
+      "created_at": "2026-07-19T18:30:00Z",
+      "source": "baseline",
+      "manifest": "scenarios/scenario-001.json"
+    },
+    {
+      "scenario_id": "scenario-002",
+      "label": "graviton (caveat: 1 incompatible \u2014 graviton applies where tier: ready; incompatible entries stay x86)",
+      "created_at": "2026-07-19T19:05:00Z",
+      "source": "workshop",
+      "manifest": "scenarios/scenario-002.json"
+    }
+  ]
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/scenarios/scenario-001.aws-design.json

@@ -0,0 +1,40 @@
+{
+  "phase": "design",
+  "services": [
+    {
+      "aws_service": "ECS Fargate",
+      "source_resource_id": "run:web",
+      "aws_config": {
+        "cpu_architecture": "X86_64",
+        "region": "us-east-1"
+      },
+      "graviton": {
+        "compatibility": "ready",
+        "target_architecture": "arm64",
+        "selected": false
+      }
+    },
+    {
+      "aws_service": "ECS Fargate",
+      "source_resource_id": "run:worker",
+      "aws_config": {
+        "cpu_architecture": "X86_64",
+        "region": "us-east-1"
+      },
+      "graviton": {
+        "compatibility": "incompatible",
+        "target_architecture": "x86_64",
+        "selected": false
+      }
+    },
+    {
+      "aws_service": "RDS PostgreSQL",
+      "source_resource_id": "sql:main",
+      "aws_config": {
+        "instance_class": "db.t4g.micro",
+        "multi_az": false,
+        "region": "us-east-1"
+      }
+    }
+  ]
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/scenarios/scenario-001.estimation-infra.json

@@ -0,0 +1,22 @@
+{
+  "phase": "estimate",
+  "pricing_source": {
+    "status": "cached"
+  },
+  "projected_costs": {
+    "aws_monthly_premium": 120.0,
+    "aws_monthly_balanced": 95.0,
+    "aws_monthly_optimized": 70.0
+  },
+  "complexity_tier": "small",
+  "recommendation": {
+    "path": "migrate_optimized",
+    "path_label": "Migrate optimized",
+    "migrate_if": [
+      "costs favor AWS"
+    ],
+    "stay_if": [
+      "heavy custom networking"
+    ]
+  }
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/scenarios/scenario-001.json

@@ -0,0 +1,20 @@
+{
+  "scenario_id": "scenario-001",
+  "label": "baseline",
+  "created_at": "2026-07-19T18:30:00Z",
+  "source": "baseline",
+  "preferences_subset": {},
+  "estimation_summary": {
+    "aws_monthly_premium": 120.0,
+    "aws_monthly_balanced": 95.0,
+    "aws_monthly_optimized": 70.0,
+    "complexity_tier": "small",
+    "pricing_source": "cached",
+    "region_note": null
+  },
+  "paths": {
+    "preferences": "scenarios/scenario-001.preferences.json",
+    "aws_design": "scenarios/scenario-001.aws-design.json",
+    "estimation_infra": "scenarios/scenario-001.estimation-infra.json"
+  }
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/scenarios/scenario-001.preferences.json

@@ -0,0 +1,37 @@
+{
+  "design_constraints": {
+    "target_region": {
+      "value": "us-east-1",
+      "chosen_by": "default",
+      "question_id": "Q1",
+      "prompt": "Where are your users located?",
+      "design_consequence": "All resources deploy in us-east-1; Bedrock model availability checked for this region"
+    },
+    "availability": {
+      "value": "single-az",
+      "chosen_by": "default",
+      "question_id": "Q6",
+      "prompt": "What level of uptime does your application require?",
+      "design_consequence": "single-az drives RDS single-AZ vs Multi-AZ vs Aurora selection"
+    },
+    "kubernetes": {
+      "value": "ecs-fargate",
+      "chosen_by": "user",
+      "question_id": "Q8",
+      "prompt": "How do you feel about Kubernetes?",
+      "design_consequence": "ecs-fargate selects EKS vs ECS Fargate vs mixed posture"
+    },
+    "cpu_architecture": {
+      "value": "x86",
+      "chosen_by": "user",
+      "question_id": "Q11b",
+      "prompt": "Some of your services have ARM64 compatibility considerations. Graviton (ARM64) instances are ~15\u201320% cheaper per hour. Your Python workloads appear compatible; worker has a linux/amd64 pin and native C extension. How would you like to proceed?",
+      "design_consequence": "x86 everywhere; forgoes the ~15\u201320% hourly discount on eligible compute"
+    }
+  },
+  "workshop": {
+    "active": true,
+    "last_sheet_at": "2026-07-19T18:30:00Z",
+    "active_scenario_id": "scenario-001"
+  }
+}

migrate/plugins/migration-to-aws/fixtures/gcp-workshop/after-graviton-reprice/scenarios/scenario-002.aws-design.json

@@ -0,0 +1,40 @@
+{
+  "phase": "design",
+  "services": [
+    {
+      "aws_service": "ECS Fargate",
+      "source_resource_id": "run:web",
+      "aws_config": {
+        "cpu_architecture": "ARM64",
+        "region": "us-east-1"
+      },
+      "graviton": {
+        "compatibility": "ready",
+        "target_architecture": "arm64",
+        "selected": true
+      }
+    },
+    {
+      "aws_service": "ECS Fargate",
+      "source_resource_id": "run:worker",
+      "aws_config": {
+        "cpu_architecture": "X86_64",
+        "region": "us-east-1"
+      },
+      "graviton": {
+        "compatibility": "incompatible",
+        "target_architecture": "x86_64",
+        "selected": false
+      }
+    },
+    {
+      "aws_service": "RDS PostgreSQL",
+      "source_resource_id": "sql:main",
+      "aws_config": {
+        "instance_class": "db.t4g.micro",
+        "multi_az": false,
+        "region": "us-east-1"
+      }
+    }
+  ]
+}