go-cotp v1.0.2

Documentation and lint hygiene. No API changes, no behavior changes.

Documentation

• Added ERRORS.md — error taxonomy covering all sentinel values, the three typed error structs
  (RejectionError, UnexpectedTPDUError, DisconnectError), ConnectionPhase constants, and
  errors.Is / errors.As usage patterns for both the service API and the codec.
• Added link to ERRORS.md in README.md Documentation section.

Linting

• Removed a stale formatters.exclusions.paths: examples entry from .golangci.yml; the
  repository has no examples/ directory so the exclusion was dead code.

No API changes. No breaking changes.

Import path remains github.com/otfabric/go-cotp.