Convert AI tagging to background job with progress tracking

- Add TaggingJob model for tracking tagging progress
- Convert batch tagging to background job processing (prevents timeouts)
- Add real-time progress polling in UI with percentage/count display
- Add admin notifications when tagging job completes or fails
- Export getTaggingSettings and getAvailableTags functions

After deployment, run: npx prisma migrate deploy

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

prisma/migrations/20260205100000_add_tagging_job/migration.sql

@@ -0,0 +1,38 @@
+-- Add TaggingJob table for background AI tagging
+DO $$ BEGIN
+    CREATE TYPE "TaggingJobStatus" AS ENUM ('PENDING', 'RUNNING', 'COMPLETED', 'FAILED');
+EXCEPTION WHEN duplicate_object THEN NULL; END $$;
+
+CREATE TABLE IF NOT EXISTS "TaggingJob" (
+    "id" TEXT NOT NULL,
+    "programId" TEXT,
+    "roundId" TEXT,
+    "status" "TaggingJobStatus" NOT NULL DEFAULT 'PENDING',
+    "totalProjects" INTEGER NOT NULL DEFAULT 0,
+    "processedCount" INTEGER NOT NULL DEFAULT 0,
+    "taggedCount" INTEGER NOT NULL DEFAULT 0,
+    "skippedCount" INTEGER NOT NULL DEFAULT 0,
+    "failedCount" INTEGER NOT NULL DEFAULT 0,
+    "errorMessage" TEXT,
+    "errorsJson" JSONB,
+    "startedAt" TIMESTAMP(3),
+    "completedAt" TIMESTAMP(3),
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "TaggingJob_pkey" PRIMARY KEY ("id")
+);
+
+CREATE INDEX IF NOT EXISTS "TaggingJob_programId_idx" ON "TaggingJob"("programId");
+CREATE INDEX IF NOT EXISTS "TaggingJob_roundId_idx" ON "TaggingJob"("roundId");
+CREATE INDEX IF NOT EXISTS "TaggingJob_status_idx" ON "TaggingJob"("status");
+
+DO $$ BEGIN
+    ALTER TABLE "TaggingJob" ADD CONSTRAINT "TaggingJob_programId_fkey"
+        FOREIGN KEY ("programId") REFERENCES "Program"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+EXCEPTION WHEN duplicate_object THEN NULL; END $$;
+
+DO $$ BEGIN
+    ALTER TABLE "TaggingJob" ADD CONSTRAINT "TaggingJob_roundId_fkey"
+        FOREIGN KEY ("roundId") REFERENCES "Round"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+EXCEPTION WHEN duplicate_object THEN NULL; END $$;