chore: update following spec changes (#59)

* chore: update following spec changes

see:
- LedgerHQ/clear-signing-erc7730-registry#32
- https://ledger.slack.com/archives/C07D03LRKHQ/p1728389147928859

* chore: update linter

src/erc7730/lint/common/paths.py

@@ -71,8 +71,12 @@ def append_paths(path: str, field: ResolvedField | None) -> None:
             match field:
                 case ResolvedFieldDescription():
                     add_path(path, field.path)
-                    if field.params and isinstance(field.params, TokenAmountParameters):
-                        add_path(path, _remove_slicing(field.params.tokenPath).strip("."))
+                    if (
+                        (params := field.params)
+                        and isinstance(params, TokenAmountParameters)
+                        and (token_path := params.tokenPath) is not None
+                    ):
+                        add_path(path, _remove_slicing(token_path).strip("."))
                 case ResolvedNestedFields():
                     for nested_field in field.fields:
                         append_paths(_append_path(path, field.path), cast(ResolvedField, nested_field))

src/erc7730/model/display.py

@@ -58,15 +58,18 @@ class TokenAmountParameters(Model):
     Token Amount Formatting Parameters.
     """
 
-    tokenPath: str = Field(
-        title="Token Path", description="The path to the token address in the structured data, or in the ERC 7730 file."
+    tokenPath: str | None = Field(
+        title="Token Path",
+        description="Path reference to the address of the token contract. Used to associate correct ticker. If ticker"
+        "is not found or tokenPath is not set, the wallet SHOULD display the raw value instead with an"
+        '"Unknown token" warning.',
     )
 
-    nativeCurrencyAddress: str | None = Field(
+    nativeCurrencyAddress: str | list[str] | None = Field(
         default=None,
         title="Native Currency Address",
-        description="An address equal to this value is interpreted as an amount in native currency rather than a"
-        "token.",
+        description="An address or array of addresses, any of which are interpreted as an amount in native currency"
+        "rather than a token.",
     )
 
     threshold: str | None = Field(

src/erc7730/model/path.py

@@ -115,6 +115,9 @@ class ContainerField(StrEnum):
     VALUE = auto()
     """The native currency value of the transaction containing the structured data."""
 
+    FROM = auto()
+    """The address of the sender of the transaction / signer of the message."""
+
     TO = auto()
     """The destination address of the containing transaction, ie the target smart contract address."""
 
@@ -228,7 +231,7 @@ def __str__(self) -> str:
         ?descriptor_path_component: field | array_element
     
         container_path: "@." container_field
-        !container_field: "to" | "value"
+        !container_field: "from" | "to" | "value"
     
         ?data_path: absolute_data_path | relative_data_path
         absolute_data_path: "#." data_path_component ("." data_path_component)*