Implement warning system enhancements with unique identifiers

- Added a `warningNumber` field to the `Warning` model for sequential identification of warnings.
- Updated the `createWarning` function to handle the new `warningNumber` logic and notify users via DM upon receiving a warning.
- Refactored moderation commands to utilize the new warning system, including changes to the warning creation and removal processes.
- Enhanced the WebUI to display warning numbers in the warnings table and updated localization for related messages.
- Documented changes in phase tracking to reflect the new warning system features.

apps/bot/prisma/migrations/20260725180000_warning_number/migration.sql

@@ -0,0 +1,16 @@
+-- AlterTable
+ALTER TABLE "Warning" ADD COLUMN "warningNumber" INTEGER;
+
+-- Backfill per-guild sequential numbers (oldest first)
+WITH numbered AS (
+  SELECT id, ROW_NUMBER() OVER (PARTITION BY "guildId" ORDER BY "createdAt" ASC, id ASC) AS rn
+  FROM "Warning"
+)
+UPDATE "Warning" AS w
+SET "warningNumber" = numbered.rn
+FROM numbered
+WHERE w.id = numbered.id;
+
+ALTER TABLE "Warning" ALTER COLUMN "warningNumber" SET NOT NULL;
+
+CREATE UNIQUE INDEX "Warning_guildId_warningNumber_key" ON "Warning"("guildId", "warningNumber");