chore(db): make the 0187 telegram-prompt-context migration rerun-safe

Guard the CREATE TABLE + both CREATE INDEX statements with IF NOT EXISTS so
a re-run on a database that already has the table is a no-op, matching the
guard convention every other recent migration ships with. Semantics are
unchanged — same table, same columns, same indexes.

prisma/migrations/0187_v1190_telegram_prompt_context/migration.sql

@@ -1,6 +1,10 @@
 -- v1.19.0 — force-reply correlation for the interactive mood reminder.
 -- Maps a bot prompt message to the entry a free-text reply attaches to.
-CREATE TABLE "telegram_prompt_contexts" (
+--
+-- Idempotent guards (`IF NOT EXISTS`) so a rerun is safe on prod. The
+-- semantics are unchanged from the original cut (same table, same columns,
+-- same indexes) — v1.19.2 added only the guards.
+CREATE TABLE IF NOT EXISTS "telegram_prompt_contexts" (
     "id" TEXT NOT NULL,
     "user_id" TEXT NOT NULL,
     "chat_id" TEXT NOT NULL,
@@ -14,7 +18,7 @@ CREATE TABLE "telegram_prompt_contexts" (
 );
 
 -- CreateIndex
-CREATE UNIQUE INDEX "telegram_prompt_contexts_chat_id_prompt_msg_id_key" ON "telegram_prompt_contexts"("chat_id", "prompt_msg_id");
+CREATE UNIQUE INDEX IF NOT EXISTS "telegram_prompt_contexts_chat_id_prompt_msg_id_key" ON "telegram_prompt_contexts"("chat_id", "prompt_msg_id");
 
 -- CreateIndex
-CREATE INDEX "telegram_prompt_contexts_expires_at_idx" ON "telegram_prompt_contexts"("expires_at");
+CREATE INDEX IF NOT EXISTS "telegram_prompt_contexts_expires_at_idx" ON "telegram_prompt_contexts"("expires_at");