add dynamic profile update, connection helper, file download metadata

- replace UserSetColor/UserSetPronouns with single UserUpdateProfile that dynamically builds one UPDATE query from UserProfileUpdateList
- add getConnectionWithResponseOnFail helper to deduplicate connection ID parsing and validation across handlers
- rename file.go to attachmentFile.go and update handler names
- GetDownloadUrlAndMetadata now fetches object metadata via StatObject and returns it alongside the presigned URL
- file download endpoint returns JSON with url and originalName
- add description field to user and DB schema
- remove unused ConnectionState variants (GroupFellow, GroupFriend)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/httpRequest/attachmentFile.go

@@ -0,0 +1,98 @@
+package httpRequest
+
+import (
+	json2 "encoding/json"
+	"net/http"
+	"strings"
+
+	"go-socket/packages/globals"
+	"go-socket/packages/minio"
+)
+
+func HandleAttachmentFileUpload(response http.ResponseWriter, request *http.Request) {
+	if !postValidCheckWithResponseOnFail(&response, request, true) {
+		return
+	}
+	ctx := request.Context()
+
+	user, err := getUserByToken(ctx, request.Header.Get("token"))
+	if err != nil {
+		http.Error(response, "invalid token", http.StatusUnauthorized)
+		return
+	}
+
+	request.Body = http.MaxBytesReader(response, request.Body, int64(globals.MaxPostWithFileBytes))
+
+	if err = request.ParseMultipartForm(int64(globals.MaxPostBytes)); err != nil {
+		http.Error(response, "invalid multipart form", http.StatusBadRequest)
+		return
+	}
+
+	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
+	if !ok {
+		return
+	}
+
+	file, header, err := request.FormFile("file")
+	if err != nil {
+		http.Error(response, "missing file", http.StatusBadRequest)
+		return
+	}
+	defer file.Close()
+
+	contentType := header.Header.Get("Content-Type")
+	key := minio.GetKey(conn.Id, contentType, minio.File)
+
+	if err = minio.Upload(ctx, key, file, header.Size, contentType, map[string]string{
+		"originalName": header.Filename,
+		"uploaderId":   user.Id.String(),
+	}); err != nil {
+		http.Error(response, "upload failed", http.StatusInternalServerError)
+		return
+	}
+
+	response.WriteHeader(http.StatusCreated)
+	response.Write([]byte(key))
+}
+
+func HandleAttachmentFileDownload(response http.ResponseWriter, request *http.Request) {
+	if !postValidCheckWithResponseOnFail(&response, request, false) {
+		return
+	}
+	ctx := request.Context()
+
+	user, err := getUserByToken(ctx, request.Header.Get("token"))
+	if err != nil {
+		http.Error(response, "invalid token", http.StatusUnauthorized)
+		return
+	}
+
+	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
+	if !ok {
+		return
+	}
+
+	key := request.FormValue("key")
+	if !strings.HasPrefix(key, conn.Id.String()+"/") {
+		http.Error(response, "no such file", http.StatusUnauthorized)
+		return
+	}
+
+	url, meta, err := minio.GetDownloadUrlAndMetadata(ctx, key)
+	if err != nil {
+		http.Error(response, "no such file", http.StatusUnauthorized)
+		return
+	}
+
+	json, err := json2.Marshal(map[string]string{
+		"url":          url.String(),
+		"originalName": meta["originalName"],
+	})
+	if err != nil {
+		http.Error(response, "metadata error", http.StatusInternalServerError)
+		return
+	}
+
+	response.WriteHeader(http.StatusOK)
+	response.Write(json)
+}