refactor: make coordinator the main workflow agent

.codex/skills/fesa-requirements-baseline/SKILL.md

@@ -13,9 +13,8 @@ Read these first:
 
 - `AGENTS.md`
 - `docs/SOLVER_AGENT_DESIGN.md`
-- `docs/requirements/README.md`
 - User feature request, target capability, constraints, and known exclusions
-- Existing `docs/requirements/<feature-id>.md` when revising a feature
+- Existing `docs/<feature-id>/requirements.md` when revising a feature
 
 ## Workflow
 
@@ -31,7 +30,7 @@ Read these first:
 
 ## Output Contract
 
-Produce or revise `docs/requirements/<feature-id>.md` with:
+Produce or revise `docs/<feature-id>/requirements.md` with:
 
 - Metadata with `feature_id`, status, owner agent, and date
 - Purpose, In Scope, Out Of Scope, and Analysis Definition
@@ -60,7 +59,8 @@ Produce or revise `docs/requirements/<feature-id>.md` with:
 - Do not require canonical names, README, metadata, provenance, or CSVs for quantities outside
   the feature acceptance boundary.
 - Words like "accurate", "fast", and "Abaqus-like" are converted into measurable criteria or open questions.
+- Return reference artifact, comparison quantity, source-identity/component, and tolerance gaps for Numerical Review rather than inventing acceptance rules.
 
 ## Handoff
 
-Route theory gaps to Research Agent, math gaps to Formulation Agent, schema gaps to I/O Definition Agent, reference artifact needs to Reference Model Agent, and implementation readiness to Implementation Planning Agent.
+Return `docs/<feature-id>/requirements.md`, status, evidence summary, and blockers to Coordinator Agent. Route theory questions to Research Agent and reference acceptance, artifact, identity/component, and tolerance questions to Numerical Review Agent through Coordinator Agent.