lint: remove unused code from platform/label_studio, email, dashboard, sync

- Delete sync/text.go, sync/tile.go, platform/dashboard.go (entirely unused)
- Remove unused vars/funcs from platform/label_studio.go (9 items)
- Remove contentEmailInitial, contentEmailReportConfirmation,
  newContentEmailNotificationConfirmation, contentEmailBase from platform/email

sync/text.go

@@ -1,17 +0,0 @@
-package sync
-
-import (
-	"context"
-	"net/http"
-
-	"github.com/Gleipnir-Technology/nidus-sync/html"
-	nhttp "github.com/Gleipnir-Technology/nidus-sync/http"
-	"github.com/Gleipnir-Technology/nidus-sync/platform"
-)
-
-type contentTextMessages struct{}
-
-func getTextMessages(ctx context.Context, r *http.Request, u platform.User) (*html.Response[contentTextMessages], *nhttp.ErrorWithStatus) {
-	content := contentTextMessages{}
-	return html.NewResponse("sync/text-messages.html", content), nil
-}

sync/tile.go

@@ -1,54 +0,0 @@
-package sync
-
-import (
-	"bytes"
-	"fmt"
-	"io"
-	"net/http"
-	"strconv"
-
-	"github.com/Gleipnir-Technology/nidus-sync/platform"
-)
-
-func getTileGPS(w http.ResponseWriter, r *http.Request, u platform.User) {
-	ctx := r.Context()
-	if err := r.ParseForm(); err != nil {
-		respondError(w, "Could not parse form", err, http.StatusBadRequest)
-		return
-	}
-	lat_s := r.FormValue("lat")
-	lng_s := r.FormValue("lng")
-	level_s := r.FormValue("level")
-	if lat_s == "" || lng_s == "" || level_s == "" {
-		respondError(w, "you must specify lat, lng, and level", nil, http.StatusBadRequest)
-		return
-	}
-
-	level, err := strconv.Atoi(level_s)
-	if err != nil {
-		respondError(w, "couldn't parse level", err, http.StatusBadRequest)
-		return
-	}
-	lat, err := strconv.ParseFloat(lat_s, 10)
-	if err != nil {
-		respondError(w, "couldn't parse lat", err, http.StatusBadRequest)
-		return
-	}
-	lng, err := strconv.ParseFloat(lng_s, 10)
-	if err != nil {
-		respondError(w, "couldn't parse lng", err, http.StatusBadRequest)
-		return
-	}
-	img, err := platform.ImageAtPoint(ctx, u.Organization, uint(level), lat, lng)
-	if err != nil {
-		respondError(w, "image at point", err, http.StatusInternalServerError)
-		return
-	}
-	w.Header().Set("Content-Type", "image/png")
-	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(img.Content)))
-	_, err = io.Copy(w, bytes.NewBuffer(img.Content))
-	if err != nil {
-		respondError(w, "copy bytes", err, http.StatusInternalServerError)
-		return
-	}
-}