Internal access to :funx application configuration.

These functions read from Application.get_env/3 with sane defaults. Used by effect modules for settings like timeouts, telemetry, and summarization.

Supported config keys

• :timeout — default timeout for running effects (default: 5_000 ms)
• :telemetry_prefix — base prefix for telemetry events (default: [:funx])
• :telemetry_enabled — whether telemetry spans are emitted (default: true)
• :summarizer — function used to summarize effect results for telemetry
• :default_span_name — fallback span name for telemetry traces