Add scoped manual Cloud integration runs

[sdairs]

Parent

• Make live Cloud integration CI selective, on-demand, and resilient #403

Dependency and stack placement

• Depends on Make live Cloud integration CI on-demand and globally serialized #404.
• Implement directly above Make live Cloud integration CI on-demand and globally serialized #404 and below Teach the OpenAPI analyzer to inventory Rust module trees #390 in the current stack.

Context

After #404 stops automatic live runs, maintainers still need a small, explicit way to run only the relevant live suite. Manual scope selection provides that value without introducing a changed-path classifier before the API module split is complete.

Scope

Add a required workflow_dispatch choice input with these values:

• all
• service
• postgres
• organization
• clickpipes

Define the scopes as follows:

Scope	Suites
all	Service, Postgres, organization, and Postgres CDC; ClickPipe smoke when its fixture variable is configured
service	Service lifecycle
postgres	Postgres lifecycle
organization	Organization lifecycle
clickpipes	Postgres CDC and optional ClickPipe smoke

• Keep selected suites sequential in the existing job.
• Skip every unselected suite without entering its test command.
• Preserve scheduled and run-cloud-integration label behavior as full all runs.
• Check out and log the exact ref/SHA selected for manual dispatch.
• Preserve the global concurrency and security behavior introduced by Make live Cloud integration CI on-demand and globally serialized #404.
• Document that a full stack validation is a manual all run against the top stack branch.

Non-goals

• Automatic affected-path classification.
• Additional labels or PR comment commands.
• Parallel suite execution.
• Retry, timeout, polling, identity, cleanup, caching, or reporting changes.

Acceptance criteria

• A maintainer can dispatch each named scope from the Actions UI.
• Each scope runs exactly the suites listed above and no others.
• all retains the current four mandatory suites and optional smoke behavior.
• A manual all run against the top branch tests the complete inherited stack snapshot.
• Label and scheduled invocations remain full runs.
• Every invocation remains globally serialized with other shared-organization mutators.