test(students): add unit, integration and e2e tests for /students (#109)

- unit: fixture shapes, mock API (GET/POST/PUT/DELETE), mock DB operations
- integration: real DB CRUD via testDb (list, filter, create, get, update, delete)
- e2e: handler calls directly with mock FreshContext + real DB
  covers auth (employee vs non-employee), 400/403/404 cases
- adds test:e2e deno task and CI step
- adds tests/helpers/handler.ts with makeEmployeeContext, makeContextWithAffiliation,
  makeGetRequest, makeJsonRequest utilities

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/helpers/handler.ts

@@ -0,0 +1,88 @@
+// Helper pour les tests E2E — appel direct des handlers Fresh
+// sans lancer de serveur HTTP
+
+import { FreshContext } from "$fresh/server.ts";
+import { AuthenticatedState } from "$root/defaults/interfaces.ts";
+import { CasContent } from "$root/defaults/interfaces.ts";
+
+const BASE_EMPLOYEE_SESSION: CasContent = {
+  amuCampus: "",
+  amuComposante: "",
+  amuDateValidation: "",
+  coGroup: "",
+  eduPersonPrimaryAffiliation: "employee",
+  eduPersonPrincipalName: "test.user@polytech.fr",
+  mail: "test.user@polytech.fr",
+  displayName: "Test User",
+  givenName: "Test",
+  memberOf: [],
+  sn: "User",
+  supannCivilite: "M.",
+  supannEntiteAffectation: "",
+  supannEtuAnneeInscription: "",
+  supannEtuEtape: "",
+  uid: "test.user",
+};
+
+/**
+ * Crée un FreshContext mock authentifié en tant qu'employee.
+ */
+export function makeEmployeeContext(
+  params: Record<string, string> = {},
+): FreshContext<AuthenticatedState> {
+  return {
+    params,
+    state: {
+      isAuthenticated: true,
+      session: { ...BASE_EMPLOYEE_SESSION },
+      availablePages: {},
+    },
+    render: () => Promise.resolve(new Response()),
+    renderNotFound: () => Promise.resolve(new Response(null, { status: 404 })),
+    next: () => Promise.resolve(new Response()),
+  } as unknown as FreshContext<AuthenticatedState>;
+}
+
+/**
+ * Crée un FreshContext mock avec un affiliation personnalisée.
+ */
+export function makeContextWithAffiliation(
+  affiliation: string,
+  params: Record<string, string> = {},
+): FreshContext<AuthenticatedState> {
+  const ctx = makeEmployeeContext(params);
+  (ctx.state as AuthenticatedState).session.eduPersonPrimaryAffiliation =
+    affiliation;
+  return ctx;
+}
+
+/**
+ * Crée une Request GET simple.
+ */
+export function makeGetRequest(
+  path: string,
+  searchParams?: Record<string, string>,
+): Request {
+  const url = new URL(`http://localhost${path}`);
+  if (searchParams) {
+    for (const [k, v] of Object.entries(searchParams)) {
+      url.searchParams.set(k, v);
+    }
+  }
+  return new Request(url.toString());
+}
+
+/**
+ * Crée une Request POST/PUT avec un corps JSON.
+ */
+export function makeJsonRequest(
+  path: string,
+  method: string,
+  body: unknown,
+): Request {
+  return new Request(`http://localhost${path}`, {
+    method,
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}