fix: image compression checkbox now shows for all raster image types

The checkbox was only shown for image/jpeg and image/png. Users
uploading WebP, GIF, AVIF, BMP, TIFF, HEIC (iPhone photos) or any
other raster format never saw the checkbox at all.

Fix: isCompressible now checks file.type.startsWith('image/') and
excludes only image/svg+xml (vector — would rasterise) and empty type
strings. compressImage signature widened to File | Blob so it matches
the TUploadContent type without unsafe casts.

The send-path guard in handleSendUpload was also widened from the
hardcoded jpeg/png check to use isCompressible(), keeping the two gates
in sync. The Blob-safe id attribute uses the .name fallback so it
doesn't break when originalFile is a Blob without a name.

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

src/app/features/room/RoomInput.tsx

@@ -67,7 +67,7 @@ import {
   mxcUrlToHttp,
   tryDeleteMxcContent,
 } from '../../utils/matrix';
-import { compressImage } from '../../utils/imageCompression';
+import { compressImage, isCompressible } from '../../utils/imageCompression';
 import { useTypingStatusUpdater } from '../../hooks/useTypingStatusUpdater';
 import { useFilePicker } from '../../hooks/useFilePicker';
 import { useFilePasteHandler } from '../../hooks/useFilePasteHandler';
@@ -412,16 +412,11 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
         // Resolve the MXC URL to use — may be overridden if compression is enabled
         let mxc = upload.mxc;
 
-        if (
-          fileItem.metadata.compressImage &&
-          fileItem.originalFile.type.startsWith('image') &&
-          (fileItem.originalFile.type === 'image/jpeg' ||
-            fileItem.originalFile.type === 'image/png')
-        ) {
+        if (fileItem.metadata.compressImage && isCompressible(fileItem.originalFile)) {
           // Use the cached compression result if available, otherwise compute it now
           let compressionResult = fileItem.metadata.compressionResult;
           if (compressionResult === undefined) {
-            compressionResult = await compressImage(fileItem.originalFile as File);
+            compressionResult = await compressImage(fileItem.originalFile);
           }
 
           if (compressionResult) {