Introduces `code.nochebuena.dev/einherjar/core` — the foundational implementation
module of the Einherjar framework. Provides four sub-packages that together cover
every service's baseline needs: lifecycle management, structured logging, typed
errors, and struct validation.
- launcher: Launcher interface — three-phase managed lifecycle (OnInit → BeforeStart
hooks → OnStart → OS signal wait → OnStop in reverse). Accepts
lifecycle.Component and logging.Logger from contracts. Prints an ASCII art banner
at startup (EINHERJAR_BANNER=off to suppress). Banner includes core version via
runtime/debug.ReadBuildInfo() and a loaded-module list for every registered
component that implements observability.Identifiable. Config struct with
EINHERJAR_COMPONENT_STOP_TIMEOUT env tag (caarlos0/env syntax, default 15s).
- logz: Logger implementation backed by log/slog. Returns contracts/logging.Logger.
Detects errs.CodedError and errs.ContextualError (from contracts/errs) to enrich
log records automatically — replaces the private duck-typed bridge from micro-lib.
Context helpers: WithRequestID, WithField, WithFields, GetRequestID. Config struct
with EINHERJAR_LOG_LEVEL (default INFO) and EINHERJAR_LOG_JSON (default false) env
tags (caarlos0/env syntax); programmatic-only fields StaticArgs and Writer carry no
tags.
- xerrors: Typed error codes with context enrichment. Complete gRPC canonical set
(16 codes) plus HTTP 410 ErrGone. Adds ErrOutOfRange, ErrAborted, ErrDataLoss
over micro-lib. One convenience constructor per code. *Err declares compile-time
satisfaction of errs.CodedError and errs.ContextualError.
- valid: Struct validation wrapping go-playground/validator/v10. Validator interface
+ MessageProvider interface with full built-in tag coverage (~150 tags) in both
DefaultMessages (English) and SpanishMessages (Spanish). Backend fully hidden;
returns *xerrors.Err with ErrInvalidInput or ErrInternal. FieldLevel interface
abstracts the backend's field-level access for custom validators.
WithCustomValidator registers custom validation tags at construction time;
OverrideProvider chains a tag→handler map with a fallback MessageProvider for
custom tag messages without re-implementing built-ins.
Compliance test enforces CT-6 (at most one exported TypeSpec per file via AST) and
verifies behavioural correctness of all four sub-packages, including custom validator
registration and OverrideProvider composition. Compile-time var _ assertions prove
interface satisfaction.
docs: ADR-001 (core module composition), ADR-002 (logz contracts/errs adoption),
ADR-003 (Config naming convention and caarlos0/env tag standard)
