## 1. OpenSpec Artifacts

- [x] 1.1 Create proposal, design, spec, and tasks for MySQL metadata storage configuration.
- [x] 1.2 Validate the change with `openspec validate add-mysql-platform-metadata-storage --strict`.

## 2. MySQL Metadata Storage

- [x] 2.1 Add platform config fields for `PLATFORM_MYSQL_DSN` and `PLATFORM_LOG_BODY_BACKEND`.
- [x] 2.2 Implement a MySQL-backed metadata snapshot store behind `repo.Store`.
- [x] 2.3 Wire router startup to support `PLATFORM_STORAGE_BACKEND=mysql`.
- [x] 2.4 Add tests for MySQL config loading, missing DSN failure, and log body backend selection.

## 3. Documentation And Comments

- [x] 3.1 Add commented MySQL examples to root/platform env examples and Docker compose.
- [x] 3.2 Update README docs with exact MySQL DSN examples and log storage guidance.

## 4. Verification

- [x] 4.1 Run `cd platform && go test ./config ./api ./repo -count=1`.
- [x] 4.2 Run `docker compose config`.
- [x] 4.3 Run `scripts/check-structure.sh`.
- [x] 4.4 Run `openspec validate add-mysql-platform-metadata-storage --strict`.