Implement fog semantic overlay integration into core spec surfaces

[mdheller]

Summary

The FogVault / FogCompute family is now merged as schemas, examples, additive OpenAPI/AsyncAPI patch fragments, and a fog vocabulary seed. The remaining contract-layer work is to integrate fog more deeply into the core semantic and architectural surfaces rather than leaving it partly staged through additive files.

Why

Right now the fog family exists and is discoverable, but the broader semantic overlay is still incomplete for full linked-data / API-self-description use.

Scope

• fold fog terms into the canonical semantic context where appropriate
• add fog-supported classes/operations into semantic/hydra.jsonld
• update ARCHITECTURE.md to include the fog layer in the contract taxonomy and plane narrative
• ensure fog patch fragments are referenced consistently from repo-level docs

Acceptance criteria

• semantic/context.jsonld maps the fog family types and core predicates
• semantic/hydra.jsonld has supported-class / operation coverage for fog resources
• ARCHITECTURE.md explicitly mentions the fog family and its relationship to execution/provenance and agent/runtime lanes
• docs do not contradict the already-merged fog schema / patch files
• changes remain additive and semver-safe

Out of scope

• changing the fog schema shapes themselves
• runtime implementation code
• deployment manifests