feat(api): endpoints to mark and unmark custom records

internal/api/handlers.go

@@ -98,6 +98,58 @@ func (a *API) handleApply(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, toChangesetResponse(cs))
 }
 
+// handleAddCustom marks an RRset as deliberately kept outside the template:
+// it moves from Prunes to its own section, stops counting as drift and can
+// never be applied. The key travels in the body, not the path — it contains
+// a space and dots ("CNAME admin.example.com.").
+func (a *API) handleAddCustom(w http.ResponseWriter, r *http.Request) {
+	pid, _ := projectIDFrom(r.Context())
+	did, err := uuid.Parse(chi.URLParam(r, "did"))
+	if err != nil {
+		writeErr(w, http.StatusBadRequest, "invalid domain id")
+		return
+	}
+	var req customRequest
+	if !decodeBody(w, r, &req) {
+		return
+	}
+	if req.Key == "" {
+		writeErr(w, http.StatusBadRequest, "key is required")
+		return
+	}
+	if err := a.Store.AddCustomRecord(r.Context(), did, pid, req.Key); err != nil {
+		// Either the domain doesn't exist or it belongs to another project —
+		// both are "not found" from this tenant's point of view.
+		log.Printf("api: add custom record failed: %v", err)
+		writeErr(w, http.StatusNotFound, "domain not found")
+		return
+	}
+	w.WriteHeader(http.StatusCreated)
+}
+
+// handleDeleteCustom removes the mark, returning the record to the regular
+// diff. The key comes as a query parameter for the same reason it comes in
+// the body on POST.
+func (a *API) handleDeleteCustom(w http.ResponseWriter, r *http.Request) {
+	pid, _ := projectIDFrom(r.Context())
+	did, err := uuid.Parse(chi.URLParam(r, "did"))
+	if err != nil {
+		writeErr(w, http.StatusBadRequest, "invalid domain id")
+		return
+	}
+	key := r.URL.Query().Get("key")
+	if key == "" {
+		writeErr(w, http.StatusBadRequest, "key is required")
+		return
+	}
+	if err := a.Store.DeleteCustomRecord(r.Context(), did, pid, key); err != nil {
+		log.Printf("api: delete custom record failed: %v", err)
+		writeErr(w, http.StatusNotFound, "domain not found")
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
 // handleZoneRecords reads a zone's current records straight from the
 // provider — no template required, no diff computed. Backs read-only zone
 // viewing for domains that don't have a template attached (yet).