feat: 实现实时匿名会话

prisma/migrations/0010_realtime_conversation/migration.sql

@@ -0,0 +1,24 @@
+-- Task 7 chat identity snapshots, query and delivery indexes.
+ALTER TABLE "messages" ADD COLUMN "sender_public_id" UUID;
+UPDATE "messages" AS m
+SET "sender_public_id" = p."public_id"
+FROM "anonymous_profiles" AS p
+WHERE p."account_id" = m."sender_id";
+-- Legacy/seed rows may predate anonymous profiles. Preserve an unlinkable
+-- snapshot instead of deriving or exposing the private account identifier.
+UPDATE "messages"
+SET "sender_public_id" = gen_random_uuid()
+WHERE "sender_public_id" IS NULL;
+ALTER TABLE "messages" ALTER COLUMN "sender_public_id" SET NOT NULL;
+
+-- Outbox events already provide durable message event dedupe.
+CREATE INDEX "messages_conversation_seq_inbox_idx"
+  ON "messages" ("conversation_id", "seq");
+CREATE INDEX "conversation_members_account_conversation_idx"
+  ON "conversation_members" ("account_id", "conversation_id")
+  WHERE "left_at" IS NULL;
+CREATE INDEX "conversations_last_message_cursor_idx"
+  ON "conversations" ("last_message_at" DESC, "id" DESC);
+CREATE INDEX "sanctions_active_account_idx"
+  ON "sanctions" ("account_id", "starts_at", "expires_at")
+  WHERE "revoked_at" IS NULL;