docs: split Structure into six linked department pages

scripts/strategy.test.mjs

@@ -15,7 +15,7 @@ test('seven existing strategy pages and two stage overviews preserve canonical r
     assert(read('sidebars/strategy.ts').includes(`'${id === 'measurement' ? 'measurement/index' : id}'`));
   }
   for (const teams of Object.values(model.organization)) for (const name of teams) {
-    assert(read('docs/organization/structure.mdx').includes(name));
+    assert(readdirSync('docs/organization/structure').some(file => read(`docs/organization/structure/${file}`).includes(name)));
     assert(read('docs/strategy/target-operating-model.mdx').includes(name));
   }
 });