feat: file upload from UI, notification dismiss, audit false positive fix

Manual file upload:
- Upload dialog in STL page with drag-and-drop file picker
- Files saved to shared Docker volume (/data/uploads)
- Worker processes via pg_notify('manual_upload') channel
- Hashes, reads metadata, splits >2GB, uploads to Telegram
- Multiple files automatically grouped
- Status polling shows upload/processing/complete states

Notification fixes:
- Add dismiss (X) button on each notification
- Add "Clear" button to remove all notifications
- Fix false positive MISSING_PART alerts from legacy packages
  (only flag when >1 destMessageIds stored but count wrong,
  not when only 1 ID from backfill)

Infrastructure:
- ManualUpload + ManualUploadFile schema + migration
- Shared manual_uploads Docker volume between app and worker
- Upload API routes (POST /api/uploads, GET /api/uploads/[id])
- Worker manual-upload processor with full pipeline

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

src/app/(app)/stls/_components/stl-table.tsx

@@ -3,7 +3,8 @@
 import { useState, useCallback, useTransition, useMemo, useRef } from "react";
 import { useRouter, usePathname, useSearchParams } from "next/navigation";
 import { toast } from "sonner";
-import { Search, Layers } from "lucide-react";
+import { Search, Layers, Upload } from "lucide-react";
+import { UploadDialog } from "./upload-dialog";
 import { useDataTable } from "@/hooks/use-data-table";
 import {
   getPackageColumns,
@@ -106,6 +107,9 @@ export function StlTable({
   // Group merge state
   const [mergeSourceId, setMergeSourceId] = useState<string | null>(null);
 
+  // Upload dialog state
+  const [uploadOpen, setUploadOpen] = useState(false);
+
   const toggleGroup = useCallback((groupId: string) => {
     setExpandedGroups((prev) => {
       const next = new Set(prev);
@@ -497,6 +501,10 @@ export function StlTable({
               </Select>
             )}
             <DataTableViewOptions table={table} />
+            <Button variant="outline" size="sm" className="h-9" onClick={() => setUploadOpen(true)}>
+              <Upload className="mr-2 h-4 w-4" />
+              Upload Files
+            </Button>
             {selectedPackages.size >= 2 && (
               <Button
                 variant="outline"
@@ -587,6 +595,8 @@ export function StlTable({
         </DialogContent>
       </Dialog>
 
+      <UploadDialog open={uploadOpen} onOpenChange={setUploadOpen} />
+
       {/* Hidden file input for group preview upload (Task 12) */}
       <input
         ref={previewInputRef}