feat(12-01): add TenderMatch/TenderNotificationPref schema + apply migration

- TenderMatch: one row per (tenderId, savedSearchId) pair, single nullable
  notifiedAt as the matched-vs-notified eligibility gate (D-06)
- TenderNotificationPref: per-user digest interval (daily/weekly/off, D-01/D-03)
- TenderSavedSearch.instantAlert: per-profile instant alert flag, default off (D-04)
- Migration 20260722100000_add_tender_notifications applied to local dev DB
  (docker exec psql), recorded in _prisma_migrations, prisma generate run

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/api/prisma/migrations/20260722100000_add_tender_notifications/migration.sql

@@ -0,0 +1,59 @@
+-- AlterTable
+-- NOTIFY-02 (D-04): Sofort-Alert pro Profil, Default AUS.
+ALTER TABLE "TenderSavedSearch" ADD COLUMN IF NOT EXISTS "instantAlert" BOOLEAN NOT NULL DEFAULT false;
+
+-- CreateTable
+-- NOTIFY-03 Kern-Invariante — der "getroffen"-Datensatz (D-06). Ein Row je
+-- (tender x savedSearch)-Paar. EIN einziges "notifiedAt" ist das
+-- Eligibility-Gate: NULL = noch nicht benachrichtigt, gesetzt (instant
+-- ODER digest) = das Paar wird NIE wieder benachrichtigt. Match-Erzeugung
+-- ist ein idempotenter Upsert auf @@unique(tenderId, savedSearchId) mit
+-- update:{} — ein Re-Match bewahrt ein bereits gesetztes notifiedAt.
+-- Scoping wie TenderTriage/TenderSavedSearch: userId ist das Scoping-Feld
+-- fuer Reads (where:{userId}, IDOR-Schutz), tenantId zusaetzlich fuer die
+-- Mandanten-SMTP-Auflösung im Digest/Instant-Versand — KEIN forTenant()/RLS.
+CREATE TABLE IF NOT EXISTS "TenderMatch" (
+    "id" TEXT NOT NULL,
+    "tenderId" TEXT NOT NULL,
+    "savedSearchId" TEXT NOT NULL,
+    "userId" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "matchedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "notifiedAt" TIMESTAMP(3),
+    "notifiedChannel" TEXT,
+
+    CONSTRAINT "TenderMatch_pkey" PRIMARY KEY ("id"),
+    CONSTRAINT "TenderMatch_tenderId_fkey" FOREIGN KEY ("tenderId") REFERENCES "Tender"("id") ON DELETE CASCADE ON UPDATE CASCADE,
+    CONSTRAINT "TenderMatch_savedSearchId_fkey" FOREIGN KEY ("savedSearchId") REFERENCES "TenderSavedSearch"("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- CreateTable
+-- NOTIFY-01 (D-03) — Digest-Intervall ist eine per-USER Einstellung, nicht
+-- pro Profil. Default 'daily' (D-01).
+CREATE TABLE IF NOT EXISTS "TenderNotificationPref" (
+    "id" TEXT NOT NULL,
+    "userId" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "digestInterval" TEXT NOT NULL DEFAULT 'daily',
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "TenderNotificationPref_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+-- Upsert-Target — ein Match je (tender x savedSearch)-Paar, idempotent.
+CREATE UNIQUE INDEX IF NOT EXISTS "TenderMatch_tenderId_savedSearchId_key" ON "TenderMatch"("tenderId", "savedSearchId");
+
+-- CreateIndex
+CREATE INDEX IF NOT EXISTS "TenderMatch_userId_idx" ON "TenderMatch"("userId");
+
+-- CreateIndex
+CREATE INDEX IF NOT EXISTS "TenderMatch_notifiedAt_idx" ON "TenderMatch"("notifiedAt");
+
+-- CreateIndex
+-- Ein Pref-Row je Nutzer.
+CREATE UNIQUE INDEX IF NOT EXISTS "TenderNotificationPref_userId_key" ON "TenderNotificationPref"("userId");
+
+-- CreateIndex
+CREATE INDEX IF NOT EXISTS "TenderNotificationPref_userId_idx" ON "TenderNotificationPref"("userId");