Moved the standards package out of internal/ so it can be imported by downstream consumers.

standards/doc.go

@@ -0,0 +1,23 @@
+// File: internal/standards/doc.go
+//
+// Package standards defines weatherfeeder’s provider-agnostic “project law”:
+//
+//   - Schema identifiers and versioning conventions (see schema.go).
+//   - Canonical interpretations / cross-provider mappings that are not specific to a
+//     single upstream API (e.g., shared code tables, text heuristics, unit policy).
+//   - Wire-format conventions for canonical payloads.
+//
+// Standards are used by both sources and normalizers. Keep this package free of
+// provider-specific logic and free of dependencies on internal/sources/* or
+// internal/normalizers/* to avoid import cycles.
+//
+// Wire-format conventions
+// -----------------------
+// For readability and stability, canonical payloads (weather.* schemas) should not emit
+// noisy floating-point representations. weatherfeeder enforces this by rounding float
+// values in canonical payloads to 4 digits after the decimal point at normalization
+// finalization time.
+//
+// Provider-specific decoding helpers and quirks live in internal/providers/<provider>.
+// Normalizer implementations and canonical mapping logic live in internal/normalizers/<provider>.
+package standards