0.29.0 — code-quality refactor (plan E1–E5): file splits, sqlc migration, SSH unification, test coverage

E1: split monolithic files — cmd/nomos (main.go → server.go + mcp.go + workers.go),
    internal/mcp/tools.go → entity_tools/ops_tools/knowledge_tools/analysis_tools,
    internal/httpapi/impl.go → domain files (entities, events, signals, ontology,
    fleet_health, client_context, client_lifecycle, entity_mutations, query_audit).
E2: migrate raw pool.Exec queries to sqlc (entities/relationships queries + generated).
E3: unify SSH — consolidate crypto/ssh dial into actuator/client.go (+client_test).
E4/E5: add tests — db/lifecycle, checkdefaults/build, ontology/preconditions, policy/risk.

internal/db/sqlcgen/entities.sql.go

@@ -177,6 +177,52 @@ func (q *Queries) ListEntities(ctx context.Context, arg ListEntitiesParams) ([]E
 	return items, nil
 }
 
+const mergeEntityAttributes = `-- name: MergeEntityAttributes :execrows
+UPDATE entities SET
+    attributes = attributes || $1::jsonb,
+    updated_at = now()
+WHERE slug = $2
+`
+
+type MergeEntityAttributesParams struct {
+	Patch []byte
+	Slug  string
+}
+
+// Shallow-merge a JSON patch into an entity's attributes (the
+// update_entity_attributes MCP/HTTP surface). Replaces the raw
+// `attributes = attributes || $2::jsonb` used in entity_tools.go.
+func (q *Queries) MergeEntityAttributes(ctx context.Context, arg MergeEntityAttributesParams) (int64, error) {
+	result, err := q.db.Exec(ctx, mergeEntityAttributes, arg.Patch, arg.Slug)
+	if err != nil {
+		return 0, err
+	}
+	return result.RowsAffected(), nil
+}
+
+const setEntityState = `-- name: SetEntityState :execrows
+UPDATE entities SET
+    state = $1,
+    updated_at = now()
+WHERE id = $2
+`
+
+type SetEntityStateParams struct {
+	State *string
+	ID    uuid.UUID
+}
+
+// Set an entity's lifecycle state by id (the set_entity_state surface, run
+// after db.ValidateTransition). Replaces the raw
+// `UPDATE entities SET state = $2 ... WHERE id = $1`.
+func (q *Queries) SetEntityState(ctx context.Context, arg SetEntityStateParams) (int64, error) {
+	result, err := q.db.Exec(ctx, setEntityState, arg.State, arg.ID)
+	if err != nil {
+		return 0, err
+	}
+	return result.RowsAffected(), nil
+}
+
 const updateEntity = `-- name: UpdateEntity :one
 UPDATE entities SET
     name = COALESCE($1, name),