Refactor Docker and Makefile configurations for improved build processes

- Updated docker-compose.tools.yml to mount source code at /src and set working directory for backend tools, ensuring proper Go module caching.
- Modified Dockerfile.tools to install the latest golangci-lint version compatible with Go 1.24 and adjusted working directory for build-time operations.
- Enhanced Makefile to build backend tools before running tests and linting, ensuring dependencies are up-to-date and improving overall workflow efficiency.
- Refactored test and handler files to include error handling for database operations, enhancing reliability and debugging capabilities.

internal/app/handlers/tile.go

@@ -55,7 +55,7 @@ func (h *Handlers) WatchGridUpdates(rw http.ResponseWriter, req *http.Request) {
 	tileCache := []services.TileCache{}
 	raw, _ := json.Marshal(tileCache)
 	fmt.Fprint(rw, "data: ")
-	rw.Write(raw)
+	_, _ = rw.Write(raw)
 	fmt.Fprint(rw, "\n\n")
 	flusher.Flush()
 
@@ -93,13 +93,13 @@ func (h *Handlers) WatchGridUpdates(rw http.ResponseWriter, req *http.Request) {
 			}
 			fmt.Fprint(rw, "event: merge\n")
 			fmt.Fprint(rw, "data: ")
-			rw.Write(raw)
+			_, _ = rw.Write(raw)
 			fmt.Fprint(rw, "\n\n")
 			flusher.Flush()
 		case <-ticker.C:
 			raw, _ := json.Marshal(tileCache)
 			fmt.Fprint(rw, "data: ")
-			rw.Write(raw)
+			_, _ = rw.Write(raw)
 			fmt.Fprint(rw, "\n\n")
 			tileCache = tileCache[:0]
 			flusher.Flush()
@@ -152,7 +152,7 @@ func (h *Handlers) GridTile(rw http.ResponseWriter, req *http.Request) {
 		rw.Header().Set("Content-Type", "image/png")
 		rw.Header().Set("Cache-Control", "private, max-age=3600")
 		rw.WriteHeader(http.StatusOK)
-		rw.Write(transparentPNG)
+		_, _ = rw.Write(transparentPNG)
 		return
 	}