fix(tests): corrige 3 suites Mocha DB revelees par leur 1er run sur main

Ces suites ont ete ecrites pendant le dev des features cooking / admin /
hors-catalogue mais jamais executees (pas de Postgres dans ces sessions).
Leur 1re execution reelle sur `main` echouait — bugs dans les tests, pas
dans le code merge.

- reference.test.ts : `GET /reference/ingredients` renvoie desormais
  `isPlaceholder` (toujours false) et `displayName` (toujours null) depuis
  la PR #16 (champs de `IngredientView`). L'assertion `to.have.keys([...])`
  exacte est mise a jour.
- cooking-session.test.ts : la fixture "pooling merged-prep" avait 2
  recettes symetriques (chop -> simmer) ; apres mise en commun du chop les
  deux simmer tournent dans l'unique phase de cuisson, donc aucun
  `background` possible (l'optimiseur est correct, cf. le test pur
  equivalent). « Tarte » recoit une etape active `mix` de plus pour que son
  simmer flotte en background pendant que « Soupe » est en hold.
- admin-tech-steps.test.ts : une requete supertest ne part qu'a l'`await`/
  `.then` ; la 1re requete /retrain concurrente n'etait jamais lancee, donc
  le verrou process n'etait jamais tenu et la 2e recevait 200 au lieu de
  409. Ajout d'un `.then(res => res, err => err)` pour la declencher avant
  l'attente de 100 ms.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/api/test/admin-tech-steps.test.ts

@@ -286,8 +286,18 @@ describe("Admin tech-steps triage", () => {
       }
       this.timeout(60000);
       const agent = await adminAgent();
-      const first = agent.post("/admin/tech-steps/retrain").send({});
-      // Let the first handler acquire the process-wide lock before the second starts.
+      // supertest requests are lazy — they only dispatch when awaited/then'd.
+      // Attaching the `.then` here is what actually fires the first request,
+      // so its handler acquires the process-wide lock before the second one
+      // (100ms later) checks it. Swallow its result/rejection — this test
+      // only asserts on the second request.
+      const first = agent
+        .post("/admin/tech-steps/retrain")
+        .send({})
+        .then(
+          (res) => res,
+          (err) => err,
+        );
       await new Promise((resolve) => setTimeout(resolve, 100));
       const second = await agent.post("/admin/tech-steps/retrain").send({});
       expect(second.status).to.equal(409);

apps/api/test/cooking-session.test.ts

@@ -105,52 +105,62 @@ describe("Cooking session", () => {
       const pieceId = await unitId("piece");
       const chopId = await techStepId("chop");
       const simmerId = await techStepId("simmer");
+      const mixId = await techStepId("mix");
 
-      /** A recipe: one pure-prep "chop onion" step, then one simmer step. */
-      async function makeRecipe(name: string, onionQty: number) {
+      /**
+       * A recipe: one pure-prep "chop onion" step, then (optionally) an
+       * active "mix" step, then one simmer step. The `withActiveStep` recipe
+       * is still doing hands-on work in the phase after its simmer starts, so
+       * the other recipe's simmer floats into that phase as `background`.
+       */
+      async function makeRecipe(name: string, onionQty: number, withActiveStep = false) {
+        const chopStep = {
+          order: 0,
+          description: "Émincer les oignons",
+          techSteps: {
+            create: [
+              {
+                techStepId: chopId,
+                order: 0,
+                ingredients: {
+                  create: [
+                    {
+                      ingredientId: onionId,
+                      quantity: onionQty,
+                      unitId: pieceId,
+                      start: 0,
+                      end: 1,
+                    },
+                  ],
+                },
+              },
+            ],
+          },
+        };
+        const activeStep = {
+          order: 1,
+          description: "Mélanger l'appareil",
+          techSteps: { create: [{ techStepId: mixId, order: 0 }] },
+        };
+        const simmerStep = {
+          order: withActiveStep ? 2 : 1,
+          description: "Faire mijoter",
+          techSteps: { create: [{ techStepId: simmerId, order: 0 }] },
+        };
         return prisma.recipe.create({
           data: {
             name,
             authorId,
             portions: 4,
             steps: {
-              create: [
-                {
-                  order: 0,
-                  description: "Émincer les oignons",
-                  techSteps: {
-                    create: [
-                      {
-                        techStepId: chopId,
-                        order: 0,
-                        ingredients: {
-                          create: [
-                            {
-                              ingredientId: onionId,
-                              quantity: onionQty,
-                              unitId: pieceId,
-                              start: 0,
-                              end: 1,
-                            },
-                          ],
-                        },
-                      },
-                    ],
-                  },
-                },
-                {
-                  order: 1,
-                  description: "Faire mijoter",
-                  techSteps: { create: [{ techStepId: simmerId, order: 0 }] },
-                },
-              ],
+              create: withActiveStep ? [chopStep, activeStep, simmerStep] : [chopStep, simmerStep],
             },
           },
         });
       }
 
       const soupe = await makeRecipe("Soupe", 2);
-      const tarte = await makeRecipe("Tarte", 3);
+      const tarte = await makeRecipe("Tarte", 3, true);
 
       const planning = await prisma.planning.create({
         data: {

apps/api/test/reference.test.ts

@@ -95,6 +95,8 @@ describe("Reference data", () => {
         "reproducible",
         "allergens",
         "diets",
+        "isPlaceholder",
+        "displayName",
       ]);
     });