feat(ui): add useModelAgreement hook for occurrence stats

Typed React Query wrapper for /occurrences/stats/model-agreement/.
Owned by this UI PR (#1308); the backend PR (#1307) is now backend-only.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: mihow

ui/src/data-services/hooks/occurrences/stats/useModelAgreement.ts

@@ -0,0 +1,71 @@
+import { API_ROUTES, API_URL } from 'data-services/constants'
+import { useAuthorizedQuery } from '../../auth/useAuthorizedQuery'
+
+interface ModelAgreementResponse {
+  project_id: number
+  total_occurrences: number
+  verified_count: number
+  verified_pct: number
+  verified_with_prediction_count: number
+  no_prediction_count: number
+  agreed_exact_count: number
+  agreed_exact_pct: number
+  agreed_any_rank_count: number
+  agreed_any_rank_pct: number
+  // Only populated when the caller passes ?agreement_coarsest_rank=<RANK>.
+  agreement_coarsest_rank: string | null
+  agreed_coarser_rank_count: number | null
+  agreed_coarser_rank_pct: number | null
+}
+
+type FilterPrimitive = string | number | boolean
+type FilterValue = FilterPrimitive | FilterPrimitive[] | null | undefined
+
+// Accepts an arbitrary filter map so the occurrence list page's filter state
+// can be threaded through unchanged (deployment, event, taxon, score
+// thresholds, apply_defaults, etc). Arrays are appended as repeated query
+// params so multi-select filters (e.g. `algorithm`, `not_algorithm`, which
+// the backend reads via `request.query_params.getlist(...)`) survive.
+export const useModelAgreement = (
+  projectId?: string,
+  filters?: Record<string, FilterValue>
+) => {
+  const url = `${API_URL}/${API_ROUTES.OCCURRENCES}/stats/model-agreement/`
+
+  const params = new URLSearchParams()
+  if (projectId) params.set('project_id', projectId)
+  if (filters) {
+    Object.entries(filters).forEach(([key, value]) => {
+      if (value === undefined || value === null || value === '') return
+      if (Array.isArray(value)) {
+        value.forEach((item) => {
+          if (item !== undefined && item !== null && item !== '') {
+            params.append(key, String(item))
+          }
+        })
+        return
+      }
+      params.set(key, String(value))
+    })
+  }
+  const queryString = params.toString()
+
+  const { data, isLoading, isFetching, error } =
+    useAuthorizedQuery<ModelAgreementResponse>({
+      queryKey: [
+        API_ROUTES.OCCURRENCES,
+        'stats',
+        'model-agreement',
+        projectId,
+        queryString,
+      ],
+      url: `${url}?${queryString}`,
+    })
+
+  return {
+    data,
+    isLoading,
+    isFetching,
+    error,
+  }
+}