Cardano Updates

matchShape's result type variable was generated from a value-namespace name
(makeRandomVariable), so implicit quantification in the signature did not bind
it and GHC reported 'not in scope'. Rebuild it as a type-variable-namespace
name. (Latent bug surfaced by the new Match activation test.)

Co-Authored-By: Claude Opus 4.8 <[email protected]>

Adds tests for internal/config covering defaults, env-var loading, YAML loading and precedence, plus reliability hardening of SaveAtomic (F_FULLFSYNC on darwin, explicit enc.Close, per-path mutex via sync.Map, unique tmp via os.CreateTemp, fsynced parent dir with propagated non-ENOTSUP errors, clearConfigEnv test helper). Fixes a precedence bug where envconfig.Process ran after yaml.Unmarshal so env silently overrode YAML and adds LoadWithFlags(configFile, *pflag.FlagSet) which snapshots and re-applies pflag-Changed values so CLI wins over YAML/env per the documented precedence; cmd/adder/main.go now uses LoadWithFlags. Effective order is now CLI > YAML > env > defaults.

BREAKING: deployments that today set an env var to override a YAML key will see the YAML value win after this change.

Closes #708

Signed-off-by: Ales Verbic <[email protected]>

The Match destructor no longer uses head/(tail^n) to index the constructor's
arguments; it binds them with an explicit list pattern

  \case args_ of { [a0, a1, ...] -> f_ (decode a0) (decode a1) ...; _ -> PlutusTx.Builtins.error () }

The wildcard branch is unreachable for well-formed Data and uses the on-chain
error builtin, matching the previous head/tail crash-on-malformed behaviour.

Adds Match/Spec.hs (deriving (AsData, Match) via Plinth) which exercises
matchShape's dispatch + field decoding at runtime, so the codegen is verified
end-to-end in CI like the AsData test.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

Store path: /nix/store/x787hxn9ss13wgpqi2g5sjnsnrv54fn7-combined-docs

- Return 410 (Gone) for discontinued signed entity types.
- Improve error response for unknown entity types with a list of
  accepted types.
- Add utility to fetch all accepted signed entity type discriminants.

- Introduced `IncompatibleSignedEntityTypeError` to handle unknown and
  discontinued entity types.
- Implemented `TryFrom` conversions for `SignedEntityType` and
  `SignedEntityTypeDiscriminants`.
- Added unit tests to validate the behavior of fallible conversions.

- remove previous `messages_parts/signed_entity_type.rs`
- rename `new` file with previous name
- adapt code

- Improve the `assert_same_json` macro to support distinct input types
  (`json` and `value`) while ignoring key order.
- Updated tests and usages to match the new macro API.

Adds `BTreeSet` for sorting and deduplication, includes helper to
retrieve all known discriminants excluding unstable values.

Temporary module name until the new message is fully tested, then it
will replace the previous messages in
`message_part/signed_entity_type.rs`.

Following adjustements from the auto-derived impl re-used from serde:
- leverage `SignedEntityTypeDiscriminantMessage` to avoid defining +
  implementing deserialize on a an enum which define only the variants
  names
- use imports instead of absolute path
- rename visitors based on their implented symbol for clarity
- remove most magic strings by using `stringify!`
- use `ok_or` instead of `match` for error handling when visiting tuple
  variants

By re-using the expanded macro of serde derive.