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/api/uploads/route.ts

@@ -0,0 +1,83 @@
+import { NextResponse } from "next/server";
+import { auth } from "@/lib/auth";
+import { prisma } from "@/lib/prisma";
+import { writeFile, mkdir } from "fs/promises";
+import path from "path";
+
+export const dynamic = "force-dynamic";
+
+const UPLOAD_DIR = process.env.UPLOAD_DIR ?? "/data/uploads";
+const MAX_FILE_SIZE = 4 * 1024 * 1024 * 1024; // 4GB per file
+
+export async function POST(request: Request) {
+  const session = await auth();
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  try {
+    const formData = await request.formData();
+    const files = formData.getAll("files") as File[];
+    const groupName = formData.get("groupName") as string | null;
+
+    if (!files.length) {
+      return NextResponse.json({ error: "No files provided" }, { status: 400 });
+    }
+
+    // Create the upload record
+    const upload = await prisma.manualUpload.create({
+      data: {
+        userId: session.user.id,
+        groupName: groupName || (files.length > 1 ? files[0].name.replace(/\.[^.]+$/, "") : null),
+        status: "PENDING",
+      },
+    });
+
+    // Save files to shared volume
+    const uploadDir = path.join(UPLOAD_DIR, upload.id);
+    await mkdir(uploadDir, { recursive: true });
+
+    for (const file of files) {
+      if (file.size > MAX_FILE_SIZE) {
+        return NextResponse.json(
+          { error: `File "${file.name}" exceeds 4GB limit` },
+          { status: 400 }
+        );
+      }
+
+      const filePath = path.join(uploadDir, file.name);
+      const buffer = Buffer.from(await file.arrayBuffer());
+      await writeFile(filePath, buffer);
+
+      await prisma.manualUploadFile.create({
+        data: {
+          uploadId: upload.id,
+          fileName: file.name,
+          filePath,
+          fileSize: BigInt(file.size),
+        },
+      });
+    }
+
+    // Notify worker
+    try {
+      await prisma.$queryRawUnsafe(
+        `SELECT pg_notify('manual_upload', $1)`,
+        upload.id
+      );
+    } catch {
+      // Best-effort
+    }
+
+    return NextResponse.json({
+      uploadId: upload.id,
+      fileCount: files.length,
+      status: "PENDING",
+    });
+  } catch (err) {
+    return NextResponse.json(
+      { error: err instanceof Error ? err.message : "Upload failed" },
+      { status: 500 }
+    );
+  }
+}