feat: add channel categories and improved creator detection

- Add category field to TelegramChannel (filterable tag like STL, PDF, D&D)
- Category column in channels table with edit via dropdown menu
- Improved creator extraction: filename patterns + channel title fallback
- extractCreatorFromChannelTitle strips [Completed], (Paid), emoji, etc.
- Fix ArchiveType in PackageListItem and PackageRow for new types
- Add Prisma migration for category column

prisma/migrations/20260321190000_add_channel_category/migration.sql

@@ -0,0 +1,5 @@
+-- AlterTable
+ALTER TABLE "telegram_channels" ADD COLUMN "category" VARCHAR(64);
+
+-- CreateIndex
+CREATE INDEX "telegram_channels_category_idx" ON "telegram_channels"("category");