Rename `Client._name` -> `Client._key_descr` so the attr actually
describes what it holds (the `key_descr` field from `brokers.toml`). In
`open_trade_dialog()` look up the account-alias via `conf['accounts']`
and raise a `ConfigurationError` with a config-file example when no
matching entry exists.
Deats,
- `api.py`: rename `name` param/attr to `key_descr`, add docstring to
`get_client()`, pull `conf['key_descr']` into a named local.
- `broker.py`: replace `acc_name` with `fqan` (fully-qualified account
name), add accounts dict validation with actionable error msg.
- `brokers.toml`: add `src_fiat`, `accounts.spot` entry, and comments
explaining the required field relationships.
(this commit-msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi
ebc5bbd42b