// Package common contains cross-provider helper code used by weatherfeeder normalizers.
//
// Purpose
// -------
// Normalizers convert provider-specific RAW payloads into canonical internal/model types.
// Some small utilities are naturally reusable across multiple providers (unit conversions,
// payload extraction, common parsing, shared fallbacks). Those belong here.
//
// This package is intentionally "boring":
//   - pure helpers (deterministic, no I/O)
//   - minimal abstractions (prefer straightforward functions)
//   - easy to unit test
//
// Numeric wire policy
// -------------------
// Canonical payloads are intended for sinks/serialization. To keep output stable and readable,
// weatherfeeder rounds floating-point values in canonical payloads to a small, fixed precision
// at finalization time (see round.go).
package common