fix(file-viewer): don't upload pasted/dropped images into a read-only editor

handlePaste/handleDrop ran the workspace image upload without checking editability, so a
read-only doc (canEdit=false or a round-trip-unsafe file) could still trigger an upload.
Guard both on view.editable.

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/rich-markdown-editor.tsx

@@ -239,13 +239,15 @@ function LoadedRichMarkdownEditor({
         return true
       },
       handlePaste: (view, event) => {
+        if (!view.editable) return false
         const images = extractImageFiles(event.clipboardData)
         if (images.length === 0) return false
         event.preventDefault()
         void insertImagesRef.current(images, view.state.selection.from)
         return true
       },
       handleDrop: (view, event) => {
+        if (!view.editable) return false
         const images = extractImageFiles(event.dataTransfer)
         if (images.length === 0) return false
         event.preventDefault()