FosferonTelemetry (fosferon_telemetry v0.1.0)

Shared failure-telemetry conventions for Fosferon Elixir apps.

Three modules:

• FosferonTelemetry.Util — UTF-8-safe truncation and exception sanitization for telemetry metadata values.
• FosferonTelemetry.FailureMetrics — generates Telemetry.Metrics.counter/2 definitions from shorthand or explicit event-name tuples.
• FosferonTelemetry.FailureHandler — generic :telemetry handler for apps whose failure events follow the canonical metadata schema (stage, error_class, error_message).