feat(gameplay): add versioned SRD rules migration

Co-authored-by: multica-agent <github@multica.ai>

README.md

@@ -18,6 +18,8 @@ To verify the complete hosted-Supabase multiplayer path (two temporary email acc
 
 Before starting either process, the root commands check the Supabase schema. If it is missing and `SUPABASE_DB_URL` is configured, they transactionally create all D&G tables, functions, triggers, indexes, and policies from `supabase/bootstrap.sql`. Copy the **Session pooler** URI from the Supabase Dashboard **Connect** panel into the root `.env` and replace the password placeholder with the URL-encoded database password. The database URL is server-only and must never use a `NUXT_PUBLIC_` prefix.
 
+Existing campaigns are upgraded automatically to ruleset version 2 by `pnpm db:ensure`. The migration preserves every round, narration, current HP, inventory, and status; adds the SRD 5.2.1 character rules profile; and records one `migrate_ruleset` audit entry per campaign. Migrated characters retain compatibility with their previous proficiency hints, while newly created characters use explicit server-owned skill, expertise, and saving-throw proficiencies.
+
 The web and worker commands both load this root `.env` file explicitly. Environment variables supplied by Railway or CI take precedence over values in the file.
 
 The UI can be built without credentials. A running Nitro server and every worker process require `SUPABASE_URL`, `SUPABASE_SERVICE_ROLE_KEY`, `NUXT_PUBLIC_SUPABASE_URL`, and `NUXT_PUBLIC_SUPABASE_ANON_KEY`; startup fails with a clear error when required server credentials are missing. Redis is optional: when `REDIS_URL` is absent, the worker safely claims jobs from the Supabase `ai_jobs` outbox using short database leases and retries failed jobs up to three times.
@@ -41,7 +43,7 @@ Use Node.js 18.20.5 or newer. The lockfile pins the web toolchain to the Node 18
 - Worlds are private by default.
 - Content is limited to 13+; explicit sexual content and sexual content involving minors are rejected.
 - AI responses are parsed against strict schemas.
-- AI can propose checks and events, but cannot directly set dice outcomes or mechanical values.
+- AI can propose checks and events, but cannot directly set dice outcomes, proficiency, temporary HP, death saves, resources, or other mechanical values.
 - SRD-derived work must retain the attribution in `LEGAL.md`.
 
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