feat(statics): add DynamicNetwork and DynamicCoin for AMS-discovered chains

[shubham-damkondwar]

Ticket: CECHO-439

[manas-at-bitgo]

Must Fix

1. token.features can be undefined — runtime crash

AmsTokenConfig.features is string[] | undefined. In buildDynamicCoin, token.features as string[] passes undefined through to BaseCoin.validateOptions(), which iterates with for...of → TypeError: options.features is not iterable.

- features: token.features as string[],
+ features: (token.features ?? []) as string[],

2. Missing denom propagation

AmsTokenConfig.denom is never passed to the DynamicCoin constructor. Cosmos-family chains (and others using denoms) will silently lose this field.

  new DynamicCoin({
    ...
    alias: token.alias,
+   denom: token.denom,
  })

Should Fix

3. EVM-centric baseUnit default

baseUnit defaults to 'wei'. For non-EVM chains (UTXO, Cosmos, Substrate), this is incorrect. Consider requiring AMS to always provide baseUnit, or use a family-aware default.

4. No unit tests

Zero test coverage for DynamicCoin, DynamicNetwork, getNetwork(), buildDynamicCoin(). At minimum:

• DynamicCoin construction with valid and edge-case AMS payloads
• getNetwork() with JSON string, plain name, and invalid input
• buildDynamicCoin() with features: undefined (the bug above)

5. getNetwork() resolution order may shadow local statics

JSON parse runs before getNetworkByName(). If AMS sends {"name": "bitcoin", "type": "mainnet", "family": "btc"}, a new DynamicNetwork is created instead of returning the existing Networks.main.bitcoin singleton. Code comparing network references (coin.network === Networks.main.bitcoin) would break.

// Check local statics first, then fall back to JSON parse
const networkObj = getNetworkByName(network);
if (networkObj) return networkObj;
// ... then try JSON parse

6. DynamicNetwork instances aren't cached

Every getNetwork() call with the same JSON string creates a new instance. If multiple AMS-discovered tokens share a network, they'll hold different objects. Consider a Map<string, DynamicNetwork> cache keyed on name+type.

[manas-at-bitgo]

lgtm