benchmarks: use registered Navier-Stokes domain

Author: Grace Lee Rui Yue

benchmarks/datasets/conjecture-probes-v1/members/navier-stokes-polynomial-certificate.toml

@@ -3,7 +3,7 @@ task_id = "navier-stokes-polynomial-certificate"
 task_name = "jacobian/navier-stokes-polynomial-certificate"
 evaluation_kind = "conjecture-probe"
 domain = "mathematical-sciences"
-primary_domain = "partial-differential-equations"
+primary_domain = "analysis"
 field = "fluid-dynamics"
 provenance_class = "authored-conjecture-probe"
 provenance_ref = "spreadsheet:unresolved-conjecture/C-006@2026-08-06"

benchmarks/datasets/conjecture-probes-v1/navier-stokes-polynomial-certificate/task.toml

@@ -10,7 +10,7 @@ keywords = ["navier-stokes", "symbolic-pde", "incompressibility", "conjecture-sc
 [metadata]
 evaluation_kind = "conjecture-probe"
 domain = "mathematical-sciences"
-primary_domain = "partial-differential-equations"
+primary_domain = "analysis"
 field = "fluid-dynamics"
 assurance_ceiling = "CHECKED"
 answer_visibility = "public"