feat(gcp): Dataplex lakes + zones + assets

[NitinKumar004]

Summary

New greenfield GCP control-plane service: Dataplex (dataplex.googleapis.com/v1), Track-1 control-plane emulation of the lakes → zones → assets hierarchy. Unmodified google.golang.org/api/dataplex clients, gcloud, and the Terraform google_dataplex_lake / google_dataplex_zone / google_dataplex_asset resources hit the handler unchanged.

Provider tier: all three resources are GA in the stable hashicorp/google provider (verified live against v5.45.2). The e2e drove them at the provider's default /v1/ base path — no /v1beta1/ needed.

What's covered

• Full CRUD + List across the three levels, every mutation LRO-wrapped and resolved inline (done:true with the resource as a typed Any, exact @type google.cloud.dataplex.v1.{Lake,Zone,Asset}), so a Terraform/SDK LRO wait terminates on the first poll.
• Hierarchy: a zone create validates its parent lake exists (404 otherwise); an asset create validates its parent lake + zone. Deleting a lake cascades to its zones and their assets; deleting a zone cascades to its assets.
• Trailing-slash-bounded prefix scans for the cascade, so deleting lake l1 never touches l10's descendants (guard test + live curl proof).
• Client-named create (?lakeId=/?zoneId=/?assetId=, body-name fallback), 409 on dup, 404 on missing parent, 400 on bad enums (zone type, resourceSpec.locationType, asset resourceSpec.type).
• updateMask top-level replace; unmasked fields survive.
• Computed-field stability (the drift point): name, deterministic uid, state=ACTIVE, lake serviceAccount, assetStatus/metastoreStatus/resourceStatus/securityStatus/discoveryStatus, createTime/updateTime — all derived from stable stored inputs and byte-identical across reads. Rich spec blocks (discoverySpec/resourceSpec/metastore) round-trip verbatim as raw passthrough.
• Shared lro.Registry wiring; Matches yields operations paths to the shared poller (no sibling operations-404 regression). COW memstore with deep clone on read; Snapshottable auto-discovered by the persist completeness test.

Live e2e (Terraform, stable hashicorp/google v5.45.2, default /v1/ path)

• apply a lake + zone + asset (labels/description/specs) → all created, LRO did not hang, states ACTIVE.
• plan -detailed-exitcode → exit 0, no drift (on uid/state/service_account/*_status/create_time + the spec blocks).
• update description + labels → applies in-place; re-plan → exit 0, clean.
• destroy → all gone (cascade verified).
• Adversarial l1/l10 prefix-collision cascade (curl): delete l1 → its children 404, l10's children survive 200.

Files

services/dataplex/driver/, providers/gcp/dataplex/, server/gcp/dataplex/; wired into providers/gcp/gcp.go, server/gcp/gcp.go (SetOperationRegistry at the shared LRO registry), server/gcp/from_provider.go; regenerated docs/coverage/ (dataplex-only diff).

Deferrals (tasks, entities, entryGroups, dataScans, environments, IAM verbs, referenced-resource data plane) are recorded out of scope.