foundation: add `queue` service-type category

[hectorvent]

Foundation: add the queue service-type category to the Cloud Explorer

Several flagship services map to a service-type category the UI does not have yet. This issue adds
the queue category once so the per-service issues that depend on it can be picked up independently.

Scope

• Add queue to CloudServiceType in packages/api/src/cloud-spi/types.ts
• Add queue to CloudServiceType in packages/frontend/src/types/cloud.ts
• Nav entry + icon + per-cloud gating in packages/frontend/src/components/Layout.tsx
  (CLOUD_SERVICE_ITEMS, CLOUD_SERVICE_ICONS)
• Handle the literal in normalizeService() in packages/frontend/src/pages/CloudExplorerPage.tsx
• Extend isServiceType() in packages/api/src/routes/clouds.ts
• Shared panel: message send/receive/peek panel (a disabled 'Queue' nav placeholder already exists)

Enables

• AWS SQS
• Azure Queue Storage

See the add-a-service pattern in any per-service issue. Generic list/create/delete/inspect is handled
by DynamicResourceView; only add a custom panel if the service needs deep UX
(models: ComputePanel, NetworkingPanel, CosmosNoSqlPanel).

[fredpena]

The issue's checklist targets the pre-SPI layout (CloudServiceType unions in types.ts and frontend types, Layout.tsx CLOUD_SERVICE_ITEMS, normalizeService, isServiceType). Types now derive from SERVICE_CATALOG; none of those spots exist as described.

The queue category already exists as messaging (catalog row: SQS / Pub/Sub / OCI Queue), merged in #157; message send/receive/delete/purge panel merged in #272; Azure Service Bus in #144.

Open PR #275 adds Azure Queue Storage via queueSchema.ts + a new catalog entry. Rule 2: that is a review, not a fresh implementation.

@hectorvent It needs to be closed or rewritten.

[hectorvent]

Closing as requested.