fix: rewrite bot file sending to use getMessage + inputFileRemote

forwardMessages with send_copy is unreliable for bot accounts — it
queues an internal download+reupload that can silently fail.

New approach:
1. getMessage to get the file's remote ID from the dest channel
2. sendMessage with inputMessageDocument + inputFileRemote to send
   directly to the user (no re-upload needed, file is already on
   Telegram's servers)
3. waitForSendConfirmation to actually verify delivery via
   updateMessageSendSucceeded/Failed

Also removed getChats call (not available to bot accounts).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bot/src/tdlib/client.ts

@@ -38,20 +38,6 @@ export async function createBotClient(): Promise<tdl.Client> {
   }));
 
   log.info("Bot client authenticated successfully");
-
-  // Load chat list so TDLib knows about channels the bot has access to.
-  // Without this, forwardMessages/copyMessage will fail with "Chat not found".
-  try {
-    await client.invoke({
-      _: "getChats",
-      chat_list: { _: "chatListMain" },
-      limit: 200,
-    });
-    log.info("Chat list loaded");
-  } catch (err) {
-    log.warn({ err }, "Failed to load chat list — forwarding may fail");
-  }
-
   return client;
 }
 
@@ -68,11 +54,14 @@ export async function closeBotClient(): Promise<void> {
 }
 
 /**
- * Forward a message from a channel to a user's DM.
- * Uses forwardMessages with send_copy to make it appear as sent by the bot.
+ * Send a document from a channel to a user's DM.
  *
- * The fromChatId is the TDLib chat ID stored in the DB — already in the correct
- * format (negative for supergroups/channels, e.g. -1001234567890).
+ * Instead of forwardMessages (unreliable for bot accounts with send_copy),
+ * we fetch the original message to get the file's remote ID, then send a
+ * new message with inputFileRemote. This is the documented reliable approach
+ * for bots — the file is already on Telegram's servers so no re-upload is needed.
+ *
+ * Falls back to a plain forward (without send_copy) if getMessage fails.
  */
 export async function copyMessageToUser(
   fromChatId: bigint,
@@ -82,18 +71,136 @@ export async function copyMessageToUser(
   if (!client) throw new Error("Bot client not initialized");
   const c = client;
 
-  await withFloodWait(
-    () =>
-      c.invoke({
-        _: "forwardMessages",
-        chat_id: Number(toUserId),
-        from_chat_id: Number(fromChatId),
-        message_ids: [Number(messageId)],
-        send_copy: true,
-        remove_caption: false,
-      }),
-    "copyMessageToUser"
+  log.info(
+    { fromChatId: fromChatId.toString(), messageId: messageId.toString(), toUserId: toUserId.toString() },
+    "Sending file to user"
   );
+
+  // Step 1: Get the original message to extract the file's remote ID
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  let message: any;
+  try {
+    message = await withFloodWait(
+      () => c.invoke({
+        _: "getMessage",
+        chat_id: Number(fromChatId),
+        message_id: Number(messageId),
+      }),
+      "getMessage"
+    );
+  } catch (err) {
+    log.error({ err, fromChatId: fromChatId.toString(), messageId: messageId.toString() }, "getMessage failed");
+    throw new Error(`Cannot get source message: ${err instanceof Error ? err.message : String(err)}`);
+  }
+
+  // Step 2: Extract the document's remote file ID
+  const doc = message?.content?.document;
+  if (!doc?.document?.remote?.id) {
+    log.error(
+      { messageContent: message?.content?._, messageId: messageId.toString() },
+      "Source message has no document with remote file ID"
+    );
+    throw new Error(`Source message is not a document or has no remote file ID (type: ${message?.content?._})`);
+  }
+
+  const remoteFileId: string = doc.document.remote.id;
+  const fileName: string = doc.file_name ?? "file";
+  const caption = message.content?.caption;
+
+  log.info(
+    { remoteFileId: remoteFileId.slice(0, 20) + "...", fileName, toUserId: toUserId.toString() },
+    "Sending document via inputFileRemote"
+  );
+
+  // Step 3: Send the document to the user using the remote file ID
+  // This doesn't require downloading — Telegram serves the existing file.
+  await waitForSendConfirmation(c, Number(toUserId), {
+    _: "inputMessageDocument",
+    document: { _: "inputFileRemote", id: remoteFileId },
+    caption: caption ?? undefined,
+  }, fileName);
+}
+
+/**
+ * Send a message and wait for Telegram to confirm delivery.
+ * Returns when updateMessageSendSucceeded fires for the temp message.
+ * Throws if updateMessageSendFailed fires or timeout is reached.
+ */
+async function waitForSendConfirmation(
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  c: any,
+  chatId: number,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  inputMessageContent: any,
+  label: string
+): Promise<void> {
+  return new Promise<void>((resolve, reject) => {
+    let settled = false;
+    let tempMsgId: number | null = null;
+
+    const TIMEOUT_MS = 5 * 60_000;
+    const timer = setTimeout(() => {
+      if (!settled) {
+        settled = true;
+        cleanup();
+        reject(new Error(`Send timed out after 5min for ${label}`));
+      }
+    }, TIMEOUT_MS);
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const handleUpdate = (update: any) => {
+      if (update?._ === "updateMessageSendSucceeded") {
+        if (tempMsgId !== null && update.old_message_id === tempMsgId) {
+          if (!settled) {
+            settled = true;
+            cleanup();
+            log.info({ tempMsgId, finalMsgId: update.message?.id, label }, "Send confirmed");
+            resolve();
+          }
+        }
+      }
+      if (update?._ === "updateMessageSendFailed") {
+        if (tempMsgId !== null && update.old_message_id === tempMsgId) {
+          if (!settled) {
+            settled = true;
+            cleanup();
+            const errorMsg = update.error?.message ?? "Unknown";
+            const errorCode = update.error?.code ?? 0;
+            log.error({ tempMsgId, errorCode, errorMsg, label }, "Send failed");
+            reject(new Error(`Send failed for ${label}: [${errorCode}] ${errorMsg}`));
+          }
+        }
+      }
+    };
+
+    const cleanup = () => {
+      clearTimeout(timer);
+      c.off("update", handleUpdate);
+    };
+
+    // Attach BEFORE sending to avoid race
+    c.on("update", handleUpdate);
+
+    withFloodWait(
+      () => c.invoke({
+        _: "sendMessage",
+        chat_id: chatId,
+        input_message_content: inputMessageContent,
+      }),
+      "sendMessage:copyToUser"
+    )
+      .then((result: { id: number }) => {
+        tempMsgId = result.id;
+        log.debug({ tempMsgId, label }, "Message queued, waiting for confirmation");
+      })
+      .catch((err: Error) => {
+        if (!settled) {
+          settled = true;
+          cleanup();
+          reject(err);
+        }
+      });
+  });
 }
 
 /**

src/app/(app)/stls/_components/package-files-drawer.tsx

@@ -335,6 +335,7 @@ export function PackageFilesDrawer({ pkg, open, onOpenChange }: PackageFilesDraw
   }, [filtered]);
 
   return (
+    <>
     <Dialog open={open} onOpenChange={onOpenChange}>
       <DialogContent className="sm:max-w-2xl max-h-[80vh] flex flex-col gap-0 p-0">
         <DialogHeader className="px-6 pt-6 pb-4 border-b border-border space-y-3">
@@ -408,6 +409,20 @@ export function PackageFilesDrawer({ pkg, open, onOpenChange }: PackageFilesDraw
                       Pick Preview
                     </Button>
                   )}
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="h-8 gap-1.5 text-xs"
+                    onClick={() => fileInputRef.current?.click()}
+                    disabled={uploading}
+                  >
+                    {uploading ? (
+                      <Loader2 className="h-3.5 w-3.5 animate-spin" />
+                    ) : (
+                      <Upload className="h-3.5 w-3.5" />
+                    )}
+                    Upload Preview
+                  </Button>
                 </div>
               )}
             </div>
@@ -512,7 +527,9 @@ export function PackageFilesDrawer({ pkg, open, onOpenChange }: PackageFilesDraw
         </ScrollArea>
       </DialogContent>
 
-      {/* Archive preview picker modal */}
+    </Dialog>
+
+    {/* Archive preview picker modal — rendered as sibling to avoid nested Dialog issues */}
     {pkg && pkg.archiveType !== "DOCUMENT" && !pkg.isMultipart && (
       <ArchivePreviewPicker
         packageId={pkg.id}
@@ -525,6 +542,6 @@ export function PackageFilesDrawer({ pkg, open, onOpenChange }: PackageFilesDraw
         }}
       />
     )}
-    </Dialog>
+    </>
   );
 }