Add SpamFeedback table migration with timestamp index (FRE-4517)

Create migration to add SpamFeedback table with indexes on:
- userId (user relationship queries)
- phoneNumberHash (anonymized lookup)
- createdAt (time-based queries, requested in FRE-4517)

packages/db/prisma/migrations/20260501184031_add_spam_feedback_table/migration.sql

@@ -0,0 +1,25 @@
+-- CreateTable
+CREATE TABLE "SpamFeedback" (
+    "id" TEXT NOT NULL,
+    "userId" TEXT NOT NULL,
+    "phoneNumber" TEXT NOT NULL,
+    "phoneNumberHash" TEXT NOT NULL,
+    "isSpam" BOOLEAN NOT NULL,
+    "label" TEXT,
+    "metadata" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "SpamFeedback_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE INDEX "SpamFeedback_userId_idx" ON "SpamFeedback"("userId");
+
+-- CreateIndex
+CREATE INDEX "SpamFeedback_phoneNumberHash_idx" ON "SpamFeedback"("phoneNumberHash");
+
+-- CreateIndex
+CREATE INDEX "SpamFeedback_createdAt_idx" ON "SpamFeedback"("createdAt");
+
+-- AddForeignKey
+ALTER TABLE "SpamFeedback" ADD CONSTRAINT "SpamFeedback_userId_fkey" FOREIGN KEY ("userId") REFERENCES "User"("id") ON DELETE CASCADE ON UPDATE CASCADE;