feat: refresh candidate traits after CV changes

Recalculate stored participant traits when job postings change and expose replacement CV uploads with live candidate refresh events.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/internal/web/handler/handler.go

@@ -297,6 +297,34 @@ func (h *Handler) CreateParticipant(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusCreated, webmapper.ParticipantToWeb(value))
 }
 
+func (h *Handler) UpdateParticipantCV(w http.ResponseWriter, r *http.Request) {
+	r.Body = http.MaxBytesReader(w, r.Body, h.maxUpload)
+	if err := r.ParseMultipartForm(h.maxUpload); err != nil {
+		writeError(w, http.StatusBadRequest, fmt.Errorf("invalid multipart form or upload too large"))
+		return
+	}
+	cv, _, filename, err := readUpload(r, "cv")
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err)
+		return
+	}
+	if len(cv) == 0 {
+		writeError(w, http.StatusBadRequest, fmt.Errorf("cv is required"))
+		return
+	}
+	participant, err := h.participants.Get(r.Context(), idParam(r))
+	if handleServiceError(w, r, err) {
+		return
+	}
+	participant.CV = cv
+	participant.CVFilename = filename
+	value, err := h.participants.Update(r.Context(), participant)
+	if handleServiceError(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, webmapper.ParticipantToWeb(value))
+}
+
 func (h *Handler) ParticipantPhoto(w http.ResponseWriter, r *http.Request) {
 	value, err := h.participants.Get(r.Context(), idParam(r))
 	if handleServiceError(w, r, err) {

backend/internal/web/router/router.go

@@ -60,6 +60,7 @@ func New(h *handler.Handler, tokens security.ITokenManager, frontendURL string)
 		protected.Get("/api/participants", h.ListParticipants)
 		protected.Post("/api/participants", h.CreateParticipant)
 		protected.Get("/api/participants/{id}", h.GetParticipant)
+		protected.Put("/api/participants/{id}/cv", h.UpdateParticipantCV)
 		protected.Get("/api/participants/{id}/photo", h.ParticipantPhoto)
 		protected.Get("/api/participants/{id}/cv", h.ParticipantCV)
 	})

backend/internal/web/router/router_test.go

@@ -47,6 +47,10 @@ func (participantStub) Get(context.Context, uint) (model.Participant, error) {
 func (participantStub) Create(context.Context, model.Participant) (model.Participant, error) {
 	return model.Participant{}, nil
 }
+func (participantStub) Update(context.Context, model.Participant) (model.Participant, error) {
+	return model.Participant{}, nil
+}
+func (participantStub) UpdateTraits(context.Context, uint) error { return nil }
 
 type questionStub struct{}