feat: add migration for skipped_packages table

Hand-written migration matching the SkippedPackage model in schema.prisma.
Will be applied automatically by docker-entrypoint.sh via `prisma migrate deploy`.

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

prisma/migrations/20260324000000_add_skipped_packages/migration.sql

@@ -0,0 +1,35 @@
+-- CreateEnum
+CREATE TYPE "SkipReason" AS ENUM ('SIZE_LIMIT', 'DOWNLOAD_FAILED', 'EXTRACT_FAILED', 'UPLOAD_FAILED');
+
+-- CreateTable
+CREATE TABLE "skipped_packages" (
+    "id" TEXT NOT NULL,
+    "fileName" TEXT NOT NULL,
+    "fileSize" BIGINT NOT NULL,
+    "reason" "SkipReason" NOT NULL,
+    "errorMessage" TEXT,
+    "sourceChannelId" TEXT NOT NULL,
+    "sourceMessageId" BIGINT NOT NULL,
+    "sourceTopicId" BIGINT,
+    "isMultipart" BOOLEAN NOT NULL DEFAULT false,
+    "partCount" INTEGER NOT NULL DEFAULT 1,
+    "accountId" TEXT NOT NULL,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "skipped_packages_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "skipped_packages_sourceChannelId_sourceMessageId_key" ON "skipped_packages"("sourceChannelId", "sourceMessageId");
+
+-- CreateIndex
+CREATE INDEX "skipped_packages_reason_idx" ON "skipped_packages"("reason");
+
+-- CreateIndex
+CREATE INDEX "skipped_packages_accountId_idx" ON "skipped_packages"("accountId");
+
+-- AddForeignKey
+ALTER TABLE "skipped_packages" ADD CONSTRAINT "skipped_packages_sourceChannelId_fkey" FOREIGN KEY ("sourceChannelId") REFERENCES "telegram_channels"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "skipped_packages" ADD CONSTRAINT "skipped_packages_accountId_fkey" FOREIGN KEY ("accountId") REFERENCES "telegram_accounts"("id") ON DELETE CASCADE ON UPDATE CASCADE;