Parse YAML frontmatter in prompts to load imports, apply provider/model/budget/iteration/tools constraints, and emit a workflow_loaded event.
Build verification surfaced a type error in workflow_loaded metadata; fixed emission to use resolved WorkflowMeta and re-ran bild Omni/Agent.hs successfully.
Added system_prompt field to WorkflowMeta; when provided, replaces default system prompt entirely.
Implemented YAML frontmatter parsing in agent: imports, provider/model, max_cost_cents, max_iterations, tools allowlist; injects workflow imports into system prompt and emits workflow_loaded event.