fix: escape double quotes in COPY CSV status field

The status field (e.g. "blocked,reason=spam,notice={...}") is quoted in
CSV for COPY protocol, but embedded double quotes from BlockingInfo
notice (JSON) were not escaped. This could break CSV parsing during
import. Now double quotes are escaped as "" per CSV spec.

src/Simplex/FileTransfer/Server/Store/Postgres.hs

@@ -26,6 +26,7 @@ import Control.Monad.Except
 import Control.Monad.IO.Class
 import Control.Monad.Trans.Except (throwE)
 import Data.ByteString (ByteString)
+import qualified Data.ByteString.Char8 as B
 import Data.ByteString.Builder (Builder)
 import qualified Data.ByteString.Builder as BB
 import qualified Data.ByteString.Lazy as LB
@@ -331,7 +332,7 @@ fileRecToCSV sId FileRec {fileInfo = FileInfo {sndKey, size, digest}, filePath,
         renderField (toField (Binary (C.encodePubKey sndKey))),
         nullable (toField <$> path),
         renderField (toField createdAt),
-        BB.char7 '"' <> renderField (toField status) <> BB.char7 '"'
+        quotedField (toField status)
       ]
 
 recipientToCSV :: RecipientId -> SenderId -> RcvPublicAuthKey -> ByteString
@@ -354,3 +355,10 @@ renderField = \case
 
 nullable :: Maybe Action -> Builder
 nullable = maybe mempty renderField
+
+quotedField :: Action -> Builder
+quotedField a = BB.char7 '"' <> escapeQuotes (renderField a) <> BB.char7 '"'
+  where
+    escapeQuotes bld =
+      let bs = LB.toStrict $ BB.toLazyByteString bld
+       in BB.byteString $ B.concatMap (\c -> if c == '"' then "\"\"" else B.singleton c) bs