feat(tests): add Jest+Supertest infrastructure with jump route suite (14 tests)

- Extract Express app creation into src/createApp.js to enable testing without starting the server
- Add Jest, Supertest, test helpers (createTestApp, auth token generator)
- Write 14 integration tests for skydive/jumps: auth protection, CRUD, ownership checks

Bugs caught and fixed by the test suite:
- MongoDB models: author field typed as Schema.Types.UUID (Mongoose 6 rejects string UUIDs) → changed to String
- Jump.toJSONFor: called toProfileJSONFor on a UUID string → guarded with typeof check
- exceptions.handler: used err.statusCode but express-jwt throws err.status → returns 500 on 401 errors
- Jump.count(query): deprecated Mongoose method was ignoring the filter → replaced with countDocuments
- jumps.routes GET /: $or query included non-schema field "title" stripped by strictQuery, leaving {} (match-all) → replaced with slug/lieu search
- $regex: was passing a JS RegExp object which serializes to {} in MongoDB → now passes raw string

src/routes/api/skydive/applications.routes.js

@@ -54,7 +54,7 @@ router.get('/', auth.required, function (req, res, next) {
                 .sort({ createdAt: 'desc' })
                 .populate('author')
                 .exec(),
-            Application.count(query).exec(),
+            Application.countDocuments(query).exec(),
             req.payload ? UserService.getUserById(req.payload.id) : null
         ]).then(function (results) {
             let applications = results[0];

src/routes/api/skydive/jumps.routes.js

@@ -39,13 +39,12 @@ router.get('/', auth.required, function (req, res, next) {
         offset = req.query.offset;
     }
     if (typeof req.query.title !== 'undefined') {
-        const rgx = new RegExp(`.*${req.query.title}.*`);
         query = {
             $or: [
-                { title: { $regex: rgx, $options: "i" } },
-                { slug: { $regex: rgx, $options: "i" } },
+                { slug: { $regex: req.query.title, $options: 'i' } },
+                { lieu: { $regex: req.query.title, $options: 'i' } },
             ],
-        }
+        };
     }
     if (typeof req.query.numeroRangeStart !== 'undefined' && typeof req.query.numeroRangeEnd !== 'undefined') {
         query.numero = {
@@ -103,7 +102,7 @@ router.get('/', auth.required, function (req, res, next) {
                 .populate('files')
                 .populate('x2data')
                 .exec(),
-            Jump.count(query).exec(),
+            Jump.countDocuments(query).exec(),
             req.payload ? UserService.getUserById(req.payload.id) : null
         ]).then(function (results) {
             let jumps = results[0];