feat: dual-mode GCP vm-rs service + gcp load_balancer modules

[anshulsao]

What

Two new dual-mode GCP modules (greenfield provision and zero-change import/adoption of an existing estate), plus the @facets/gcp-load-balancer output type.

module	intent/flavor	what
modules/service/vm-rs/1.0	service / vm-rs	VM-backed service modelled as Deployment / StatefulSet on raw GCE VMs (zonal + regional PD, shielded, per-replica placement). Boot image is an artifact input (Packer/GCE image → CI → release replaces the VM). Output @facets/service.
modules/load_balancer/gcp/1.0	load_balancer / gcp	Global external/internal HTTP(S) L7 LB stack (address → forwarding rule → proxy → url map → backend service → unmanaged instance group, + optional :80→:443 redirect). Managed-cert greenfield path + 0-change adoption. Output @facets/gcp-load-balancer (new, under outputs/).

Dual mode

Both select behaviour by whether the imports.* pins are set:

• empty → greenfield: vm-rs provisions fresh VMs+disks; load_balancer creates the IP + a managed SSL cert + the full stack.
• set → adopt: reproduces an existing hand-rolled estate 0-change via targeted ignore_changes on the volatile/computed/ForceNew attributes; foundation (static IP, SSL certs) is referenced, never created.

Provenance / testing

Both modules were built and hardened adopting a full production GCP estate — 44 standalone VMs + 28 LB stacks — at a verified 0-change (0 add/change/destroy), then greenfield-validated in a fresh region (VM + full LB stack create cleanly, zero import blocks). Generalized here (no customer-specific values).

Placement / taxonomy — maintainer input welcome

• load_balancer/gcp — placed under the first-class load_balancer intent to match modules/load_balancer/vultr. ✅
• service/vm-rs — kept as intent: service (a VM-backed service, deliberately modelled Deployment/StatefulSet for a clean path to MIG/GKE later), with a functional flavor vm-rs alongside the cloud-named service flavors. Alternative: intent: compute / flavor: gcp (there is a modules/compute/vultr). Happy to move it if you prefer that taxonomy.
• output.facets.yaml is gitignored per repo convention; the LB output type lives in outputs/gcp-load-balancer/outputs.yaml.
• version.tf pins hashicorp/google (module resources) + Facets-cloud/facets.

Still to do before un-drafting

• Validate against a GCP project-type in CI (raptor module validate).
• Confirm final intent/flavor taxonomy per above.

🤖 Generated with Claude Code

https://claude.ai/code/session_01RsiV1JkMqt96ZQb1brv4zq