Fix private calls

toju-app/src/app/domains/attachment/README.md

@@ -76,6 +76,8 @@ graph TD
 
 Files move between peers using a request/response pattern over the WebRTC data channel. The sender announces a file, the receiver requests it, and chunks flow back one by one.
 
+When Electron serves a file from disk, the sender reads one chunk at a time and uses the buffered data-channel send path so large saved media does not get loaded into renderer memory or flood the receiver.
+
 ```mermaid
 sequenceDiagram
     participant S as Sender
@@ -90,12 +92,12 @@ sequenceDiagram
 
     loop Every 64 KB chunk
         S->>R: file-chunk (attachmentId, index, data, progress, speed)
-        Note over R: Append to chunk buffer
+        Note over R: Append to chunk buffer, or append media directly to disk on Electron
         Note over R: Update progress + EWMA speed
     end
 
     Note over R: All chunks received
-    Note over R: Reassemble blob
+    Note over R: Reassemble blob, or open completed Electron media from disk
     Note over R: shouldPersistDownloadedAttachment? Save to disk
 ```
 
@@ -131,17 +133,27 @@ When the user navigates to a room, the manager watches the route and decides whi
 
 The decision lives in `shouldAutoRequestWhenWatched()` which calls `isAttachmentMedia()` and checks against `MAX_AUTO_SAVE_SIZE_BYTES`.
 
+Browser chat views render audio/video larger than 50 MB with the same generic file interface as other downloads, even after the bytes are available. Attachments with audio/video MIME types that Chromium reports as unsupported also use the generic file interface instead of a broken native player.
+
+An optional experimental VLC.js adapter can be enabled from General settings. When enabled, unsupported downloaded audio/video files show a manual Play action that lazy-loads `/vlcjs/metoyou-vlc-player.js`. The runtime is intentionally isolated in the experimental media domain and is not part of the default attachment path.
+
 ## Persistence
 
-On Electron, completed downloads are written to the app-data directory. The storage path is resolved per room and bucket:
+On Electron, local audio/video uploads are played through the original filesystem path when Electron exposes one, and received audio/video downloads are appended to an app-data file as chunks arrive. Completed audio/video downloads are then played through a file-backed media URL instead of being reloaded into a renderer `Blob`, which avoids full-file renderer memory pressure during download, startup restore, and playback. The storage path for downloaded server-room files is resolved per room and bucket:
 
 ```
-{appDataPath}/{serverId}/{roomName}/{bucket}/{attachmentId}.{ext?}
+{appDataPath}/server/{roomName}/{bucket}/{attachmentId}.{ext?}
 ```
 
-Room names are sanitised to remove filesystem-unsafe characters. The bucket is either `attachments` or `media` depending on the attachment type. The original filename is kept in attachment metadata for display and downloads, but the stored file uses the attachment ID plus the original extension so two uploads with the same visible name do not overwrite each other.
+Direct-message attachments use the conversation id instead of the server-room path:
 
-`AttachmentPersistenceService` handles startup migration from an older localStorage-based format into the database, and restores attachment metadata from the DB on init. On browser builds, files stay in memory only.
+```
+{appDataPath}/direct-messages/{conversationId}/{bucket}/{attachmentId}.{ext?}
+```
+
+Room and conversation names are sanitised to remove filesystem-unsafe characters. The bucket is `video`, `audio`, `image`, or `files` depending on the attachment type. The original filename is kept in attachment metadata for display and downloads, but the stored file uses the attachment ID plus the original extension so two uploads with the same visible name do not overwrite each other.
+
+`AttachmentPersistenceService` handles startup migration from an older localStorage-based format into the database, and restores attachment metadata from the DB on init. On Electron, saved audio/video records are restored as file-backed URLs; other restored files still need their bytes loaded when a `Blob` URL is required. On browser builds, files stay in memory only.
 
 ## Runtime store