Integrate embeddinglab as Holmes SourceOS carry pilot

[mdheller]

Implement the first governed lab-family slice for embeddinglab as the Holmes pilot.

Scope:

• Add functional-service.v1 manifest for embeddinglab.
• Add deterministic smoke input/output/evidence fixtures.
• Add make validate and make smoke targets.
• Add SourceOS carry emission script and example output.
• Keep all model weights and mutable adapters out of the repo.

Acceptance criteria:

• make validate passes.
• make smoke passes without network access.
• manifests/functional-service.json conforms to SocioProphet/functional-model-surfaces functional-service.v1.
• emitted SourceOS carry object is disabled by default, local-only by default, signed-reference-ready, and carries no mutable model state.
• Holmes integration references embeddinglab as the pilot functional lab surface.

Related repos:

• SocioProphet/holmes
• SocioProphet/functional-model-surfaces
• SourceOS-Linux/sourceos-model-carry
• SocioProphet/sociosphere