fix(admin): bypass admin/stats + shared barrels in server router

Follow-up to 'avoid ~/modules/shared barrel in server-only router':
the first fix only changed the direct import, but adminStats.ts still
went through the `~/modules/admin/stats` barrel for schemas + types.
That barrel re-exports `ConformiteStatsPage` (client component), which
in turn imports from `~/modules/shared` → `useZodForm` /
`useDsfrModal` → the `react-server` build of `react-hook-form` that
does not export `useForm` / `useRef`. The Next.js dev overlay kept
surfacing the same error even though the build passed in CI (turbopack
vs webpack difference).

Switch every import in the router to internal file paths
(`~/modules/admin/stats/{schemas,types}` and `~/modules/shared/nafSections`)
and document the trade-off with a comment block. The proper long-term
fix is to split each barrel into client / server halves.

Author: LucasCharrier

packages/app/src/server/api/routers/adminStats.ts

@@ -10,24 +10,27 @@ import {
 	sql,
 } from "drizzle-orm";
 
+// Server-only router: every import below bypasses the `~/modules/admin/stats`
+// and `~/modules/shared` barrels and targets internal files instead. Those
+// barrels re-export React-only code (`ConformiteStatsPage`, `useZodForm`,
+// `useDsfrModal`) whose dependency chain ends in `react-hook-form`'s
+// `react-server.esm.mjs` build — which does not expose `useForm`. Indirect
+// imports from server code therefore fail at `next build` and the dev
+// server error overlay. Hitting files directly is ugly but correct until
+// the barrels get split into client/server halves.
+import {
+	getCampaignProgressionSchema,
+	getGapAlertRateSchema,
+	getMultiYearGapTrendSchema,
+} from "~/modules/admin/stats/schemas";
 import type {
 	CampaignProgressionPoint,
 	CampaignProgressionSeries,
 	GapAlertRateResult,
 	MultiYearGapPoint,
 	MultiYearGapTrendSeries,
-} from "~/modules/admin/stats";
-import {
-	getCampaignProgressionSchema,
-	getGapAlertRateSchema,
-	getMultiYearGapTrendSchema,
-} from "~/modules/admin/stats";
+} from "~/modules/admin/stats/types";
 import { COMPANY_SIZE_RANGES } from "~/modules/domain";
-// Server-only router: import the constants directly from the internal file
-// instead of the `~/modules/shared` barrel, which also re-exports the
-// `useZodForm` client hook. The barrel pulls `react-hook-form`, and its
-// server build (`react-server.esm.mjs`) does not export `useForm`, so
-// indirect imports from server code break `next build`.
 import {
 	DOMINANT_NAF_SECTIONS,
 	OTHER_NAF_SEGMENT,