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/console/v1/schema.graphql

@@ -1572,6 +1572,7 @@ input DocumentFilter {
 input MeasureFilter {
     query: String
     state: MeasureState
+    category: String
 }
 
 input RiskFilter {
@@ -1857,6 +1858,8 @@ type Organization implements Node {
         filter: StateOfApplicabilityFilter = { snapshotId: null }
     ): StateOfApplicabilityConnection! @goField(forceResolver: true)
 
+    measureCategories: [String!]! @goField(forceResolver: true)
+
     measures(
         first: Int
         after: CursorKey