Refactor MeasuresPage to use Relay fragments

Replace the client-side grouped-by-category view (fetching 500 items)
with a flat table using server-side filtering and cursor-based
pagination. Colocate GraphQL queries, fragments, and mutations in the
component file per console CLAUDE.md conventions.

Backend changes add a category filter to the measure list endpoints
(GraphQL, MCP) and a new measureCategories field on Organization.

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/server/api/mcp/v1/schema.resolvers.go

@@ -380,9 +380,9 @@ func (r *Resolver) ListMeasuresTool(ctx context.Context, req *mcp.CallToolReques
 
 	cursor := types.NewCursor(input.Size, input.Cursor, pageOrderBy)
 
-	var measureFilter = coredata.NewMeasureFilter(nil, nil)
+	var measureFilter = coredata.NewMeasureFilter(nil, nil, nil)
 	if input.Filter != nil {
-		measureFilter = coredata.NewMeasureFilter(input.Filter.Query, input.Filter.State)
+		measureFilter = coredata.NewMeasureFilter(input.Filter.Query, input.Filter.State, input.Filter.Category)
 	}
 
 	page, err := prb.Measures.ListForOrganizationID(ctx, input.OrganizationID, cursor, measureFilter)
@@ -1624,7 +1624,7 @@ func (r *Resolver) ListControlMeasuresTool(ctx context.Context, req *mcp.CallToo
 
 	cursor := types.NewCursor(input.Size, input.Cursor, pageOrderBy)
 
-	measurePage, err := prb.Measures.ListForControlID(ctx, input.ControlID, cursor, coredata.NewMeasureFilter(nil, nil))
+	measurePage, err := prb.Measures.ListForControlID(ctx, input.ControlID, cursor, coredata.NewMeasureFilter(nil, nil, nil))
 	if err != nil {
 		return nil, types.ListControlMeasuresOutput{}, fmt.Errorf("failed to list control measures: %w", err)
 	}

pkg/server/api/mcp/v1/specification.yaml

@@ -1434,6 +1434,9 @@ components:
             state:
               $ref: "#/components/schemas/MeasureState"
               description: Measure state filter
+            category:
+              type: string
+              description: Filter by measure category
 
     ListMeasuresOutput:
       type: object