TOML / INI / HCL / .env / Nix / dotenv ⇄ Kubernetes ConfigMap & Secret Config Format Bridge

Every format parses into a typed intermediate tree: scalar types (string/int/float/bool/null), lists, nested objects, HCL block labels and interpolation placeholders all keep their provenance. dotenv values are always strings (their real semantics); bare INI/.properties values are inferred as int/float/bool and flagged as inferred, while quoted values stay strings; HCL expressions (functions, references) are kept verbatim with a note; the Nix reader supports let … in, inherit, dotted attribute paths and ''…'' indented strings, marking lambdas and unresolved references instead of failing. ConfigMap/Secret manifests use stringData (the server merges it; Kubernetes applies the base64 encoding for Secrets) and keys are sanitized to the K8s charset (alphanumeric, '-', '_', '.'). The round-trip diff re-parses the emitted output and compares it key by key with the source tree, reporting dropped/added/type/value classes — exactly the list a human should review during a cross-format migration. TOML and YAML parsing use the battle-tested @iarna/toml and js-yaml libraries; the dotenv/INI/properties/HCL/Nix sides are bounded subsets with line-precise errors.