- add Config.Charset (MYSQL_CHARSET, default "utf8mb4"): connection character set
sent as SET NAMES during handshake; previously hardcoded
- add Config.Loc (MYSQL_LOC, default "UTC"): IANA timezone for time.Time ↔
DATE/DATETIME conversion; previously hardcoded
- add Config.ParseTime (MYSQL_PARSE_TIME, default "true"): driver-level DATE/DATETIME
→ time.Time mapping; valid values "true"/"false"; previously hardcoded
- update DSN() to derive parameters from Config fields with empty-means-default
semantics; existing Config literals produce identical DSN output (backward compatible)
- remove unused url.URL construction from DSN(); params now built directly via url.Values
- document collation DSN limitation in Config godoc, CLAUDE.md, RELEASE.md, CHANGELOG.md:
go-sql-driver v1.8.x uses 1-byte handshake collation IDs (max 255); MariaDB 11.4+
collations such as utf8mb4_uca1400_as_cs exceed that range — set collation at the
database/table level in schema migrations instead
database/sql-backed MySQL client with launcher lifecycle, health check, unit-of-work via context injection, and structured error mapping.
What's included:
- Executor / Tx / Client / Component interfaces using database/sql native types (sql.Result, *sql.Rows, *sql.Row)
- Tx.Commit() / Tx.Rollback() without ctx, matching the honest database/sql contract
- New(logger, cfg) constructor; *sql.DB opened in OnInit
- Config struct with env-tag support for all pool tuning parameters
- UnitOfWork via context injection; GetExecutor(ctx) returns active *sql.Tx or *sql.DB
- HandleError mapping MySQLError.Number to xerrors codes (1062 → AlreadyExists, 1216/1217/1451/1452 → InvalidInput, ErrNoRows → NotFound)
- Driver imported as mysqldrv alias to avoid package name collision
- health.Checkable at LevelCritical; HealthCheck delegates to db.PingContext
Tested-via: todo-api POC integration
Reviewed-against: docs/adr/
