feat: add admin pricing workflow

Add the admin pricing observation and valuation form, secure valuation writes with CSRF, and extend authenticated browser coverage.

apps/api/tests/http/pricing-routes.test.js

@@ -24,5 +24,5 @@ test('accepts a protected pricing observation and valuation request', async (tes
   assert.equal(observationResponse.statusCode, 201);
   assert.equal(valuationResponse.statusCode, 200);
   assert.equal(valuationResponse.json().data.valueMinor, 2500);
-  assert.equal(csrfChecks, 1);
+  assert.equal(csrfChecks, 2);
 });